TB-500 (Ac-LKKTETQ)

Evidence

TB-500 (Ac-LKKTETQ) vs LKKTETQ vs Full-Length Thymosin

β4

Actin Biology • Cell Migration • Wound-Healing Research • Experimental Musculoskeletal

Recovery

At a Glance

What is TB-500?

For Navaro, TB-500 should refer specifically to the molecule FDA currently defines as TB-500 , rather than automatically being used as another name for full-length thymosin β4.

FDA defines TB-500 free base as a synthetic seven-amino-acid fragment corresponding to residues 17-23 of full-length thymosin β4, with an acetyl group attached to the N-terminal leucine.

FDA-defined TB-500 sequence Ac-LKKTETQ or:

N-acetyl-Leu-Lys-Lys-Thr-Glu-Thr-Gln FDA reports a molecular weight of approximately 889.01 g/mol for TB-500 free base. FDA evaluates TB-500 free base and TB-500 acetate as different bulk drug substances.

There Are Actually Three Molecules to Keep Separate

The identity problem is more complicated than simply:

TB-500 ≠ thymosin β4 There are at least three relevant molecular categories.

1. FDA-Defined TB-500

Ac-LKKTETQ Seven amino acids.

N-terminally acetylated.

Corresponds to thymosin β4 residues 17-23.

2. Non-Acetylated LKKTETQ

LKKTETQ Also seven amino acids.

But:

no N-terminal acetyl group That chemical difference matters.

FDA specifically warns that acetylation can change peptide:

• charge

• hydrophobicity

• size

• lifespan

• folding characteristics

• binding properties

Therefore, pharmacology observed with plain LKKTETQ should not automatically be transferred to Ac- LKKTETQ TB-500.

3. Full-Length Thymosin β4

Full-length human thymosin β4, or Tβ4, is a naturally occurring peptide containing:

43 amino acids It has a substantially larger mechanistic, animal and human research program than either short fragment.

FDA’s review likewise distinguishes full-length Tβ4 from the seven-amino-acid TB-500 fragment.

Core Identity Rule

Ac-LKKTETQ ≠ LKKTETQ ≠ full-length Tβ4 These molecules are related.

They are not interchangeable.

Every study, protocol, vial and safety claim should be classified according to the exact molecule involved before the evidence is transferred to Navaro.

Why the Naming Problem Is So Severe

The term TB-500 has been used inconsistently across:

• peptide vendors

• anti-doping literature

• research summaries

• community protocol sites

• clinic websites

• scientific papers

FDA itself found substantial identity problems even within the formal nomination package it reviewed.

The nomination referred to TB-500 free base, while the accompanying certificate of analysis appeared to describe TB-500 acetate. FDA also found inconsistencies involving CAS numbers, molecular formula information and chemical identification.

Production rule A vial labeled only:

TB-500 EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 2

should not automatically be assumed to identify the exact molecule.

Where possible, verify:

Exact peptide: ___ Sequence: ___ Length: 7 aa or 43 aa N-terminal acetylation: Yes / No Form: Free base / acetate / other Molecular weight: ___ A product containing the complete 43-amino-acid molecule should be classified as:

full-length thymosin β4 even if its vendor markets it as TB-500.

How Well Studied Is It?

FDA-Defined Ac-LKKTETQ TB-500

Evidence area Assessment Direct human administration None verified by FDA Human SC efficacy Not established Human IM efficacy Not established Human dose-finding Not established Human PK Not established Human safety Not established Direct in-vitro wound-healing evidence Limited and not clearly positive Exact-fragment animal PK Exists Exact-fragment in-vivo efficacy Very limited / uncertain Long-term toxicity Not established FDA’s May 2026 evaluation states that it did not identify human administration data for TB-500 free base or TB-500 acetate through any route . FDA also found major gaps in acute toxicity, repeat-dose toxicity, genotoxicity, reproductive toxicity and carcinogenicity.

Overall evidence strength Very limited

Non-Acetylated LKKTETQ

Evidence area Assessment Human therapeutic evidence Not established Preclinical wound research Limited positive evidence Chemical equivalence to Ac-LKKTETQ No An older aged-mouse wound study used non-acetylated LKKTETQ, not FDA-defined TB-500.

Topical 0.01% LKKTETQ was associated with greater epidermal closure and collagen content by day 7 compared with vehicle in that model. FDA specifically warns that this finding cannot simply be transferred to the acetylated TB-500 molecule.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 3

Full-Length Thymosin β4

Evidence area Assessment Mechanistic research Meaningful / extensive Animal research Meaningful / extensive Human IV exposure Yes Human Phase 1 safety / PK Yes Human topical wound research Yes Human ophthalmic research Yes Human cardiovascular research Yes Human systemic musculoskeletal efficacy Not established Community-style SC sports-injury dosing Not established The major human evidence commonly associated online with “TB-500” belongs overwhelmingly to fulllength thymosin β4 , not the seven-amino-acid fragment.

Critical Evidence Rule

It is misleading to write:

“TB-500 has Phase 1 human safety data.”

without identifying the molecule.

The proper wording is:

Full-length thymosin β4 has human Phase 1 safety and pharmacokinetic research. FDA-defined Ac- LKKTETQ TB-500 does not currently have verified human administration data.

What May FDA-Defined TB-500 Help With?

Human evidence

Not established FDA did not identify clinical evidence showing that Ac-LKKTETQ TB-500 treats any disease or wound condition in humans.

Exact Ac-LKKTETQ Laboratory Evidence

This section is especially important because the direct fragment data are weaker than the broad thymosin literature makes them appear .

FDA reviewed a 2024 fibroblast scratch-wound experiment using:

TB-500 free base, Ac-LKKTETQ at:

50 μg/mL After eight hours, wound closure was not significantly different from vehicle .

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 4

Important metabolite finding Under the same conditions, the TB-500 metabolite:

N-acetylated LKKTE at:

50 μg/mL produced a small but statistically significant increase in wound closure.

Why this matters It raises an unresolved mechanistic question:

Could some biological effects attributed to TB-500 depend partly on metabolism into shorter peptides rather than the intact Ac-LKKTETQ molecule itself?

FDA explicitly states that this remains unknown.

Evidence classification Direct N-acetylated TB-500 pharmacology: Very limited and mixed

Non-Acetylated LKKTETQ Wound Research

The positive classic fragment study used:

plain LKKTETQ not:

Ac-LKKTETQ In aged mice with experimental skin wounds, topical non-acetylated LKKTETQ was associated with increased epidermal closure and collagen content.

Critical distinction Positive LKKTETQ evidence cannot automatically be counted as positive Ac-LKKTETQ evidence.

Acetylation changes molecular properties.

Correct evidence classification Related fragment evidence not:

Direct TB-500 proof

July 2026 Achilles-Tendon Study

A new animal study published in 2026 evaluated a product identified by the investigators as TB-500 in a rat Achilles rupture-and-repair model.

Thirty-two rats were assigned to:

• control

• BPC-157

• TB-500

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 5

• BPC-157 + TB-500

The study used:

BPC-157: 10 μg/kg/day and:

TB-500: 60 μg/kg/day given intraperitoneally for approximately 30 days.

What the Study Found

The TB-500 group showed:

• significantly greater maximum load to failure versus controls

• improved total Bonar histopathology score

• improved total Movin score

• improved collagen organization

• evidence consistent with more advanced matrix remodeling

The authors interpreted the findings as preliminary evidence supporting further study.

Evidence classification Positive exploratory rat tendon evidence

Critical Identity Limitation of the Achilles Study

The paper identifies its product as:

TB-500, product 27-155-PS, Peptide Sciences but does not report enough independent analytical information in the publication to confirm:

• amino-acid sequence

• N-terminal acetylation

• molecular weight

• free-base versus salt status

The authors also state that their 60 μg/kg/day dose was selected from biologically active full-length Tβ4 preclinical dose ranges , rather than from formal TB-500 tendon dose-optimization studies.

Correct production wording 2026 rat Achilles study: A commercial product identified by investigators as TB-500 improved several tendon-healing measures in rats, including maximum load to failure. However , the paper does not adequately establish whether the tested material was FDA-defined Ac-LKKTETQ, non-acetylated LKKTETQ, or another thymosin-related commercial preparation. The result therefore belongs under TB-500-labeled animal evidence with an identity limitation , not definitive Ac-LKKTETQ evidence.

What May Full-Length Thymosin β4 Help With?

Human evidence exists in several route-specific areas.

Better-established human research categories

• short-term IV safety and pharmacokinetics

• topical chronic-wound research

• ophthalmic corneal research

• cardiovascular research

What remains unestablished Full-length Tβ4 has not been clinically established as a systemic SC sports-recovery treatment for:

• tendon tears

• ligament injuries

• muscle injuries

• joint repair

• cartilage regeneration

• athletic recovery

Human Full-Length Tβ4 Evidence

1. Earlier IV Healthy-Volunteer Study

A 2010 randomized placebo-controlled study administered synthetic full-length Tβ4 intravenously to healthy volunteers.

Single-dose cohorts received:

• 42 mg

• 140 mg

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 7

• 420 mg

• 1,260 mg

Participants then received the same study-specific dose daily for 14 days after safety review.

The treatment was reported as generally well tolerated over the short trial.

What this supports

• genuine systemic human exposure to full-length Tβ4

• short-term human IV tolerability research

What it does not support

• Ac-LKKTETQ safety

• 2 mg TB-500 SC

• 4 mg TB-500 SC

• twice-weekly community use

• sports-injury treatment

3. Full-Length Tβ4 Venous-Ulcer Research

A randomized human Phase 2 study enrolled 73 patients with venous stasis ulcers and evaluated topical full-length thymosin β4.

The study reported a wound-healing signal, with 0.03% Tβ4 identified as a potentially useful concentration in that research program.

Evidence classification Human topical full-length Tβ4 evidence not:

Human TB-500 fragment evidence

4. Pressure-Ulcer Clinical Research

Full-length Tβ4 has also been studied topically in controlled pressure-ulcer research programs. ClinicalTrials.gov records a double-blind placebo-controlled study designed to assess safety, tolerability and woundhealing efficacy.

Again:

Topical full-length Tβ4 wound research does not establish a systemic SC TB-500 protocol.

5. Ophthalmic Full-Length Tβ4 Research

Full-length Tβ4 has progressed into Phase 3 ophthalmic development as:

RGN-259 a 0.1% Tβ4 ophthalmic solution.

In the small SEER-1 neurotrophic-keratopathy trial:

6 of 10 RGN-259-treated participants achieved complete healing at approximately four weeks compared with:

1 of 8 placebo-treated participants.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 9

The primary four-week comparison produced a strong numerical signal but narrowly missed conventional statistical significance. Later healing and symptom measures were more favorable.

Correct production wording SEER-1 Phase 3 showed a strong numerical corneal-healing signal with full-length Tβ4 ophthalmic solution, but the prespecified four-week primary comparison narrowly missed conventional statistical significance. Additional later healing and symptom outcomes favored RGN-259.

Do not write “Phase 3 proved Tβ4 heals corneas.”

That is too strong.

6. 2025 Full-Length Tβ4 STEMI Trial

A 2025 randomized, double-blind, placebo-controlled clinical trial evaluated recombinant human fulllength Tβ4 in:

96 patients with ST-elevation myocardial infarction after PCI.

Overall randomized population The overall difference in infarct area between Tβ4 and placebo was:

not statistically significant Early-treatment subgroup Among participants who received their first Tβ4 dose within approximately:

8 hours after PCI the rhTβ4 group showed a significantly smaller infarct area at the 90-day follow-up compared with placebo.

Correct production wording 2025 STEMI trial: Full-length recombinant human Tβ4 was tested in a randomized controlled myocardialinfarction trial. The complete randomized population did not show a statistically significant infarct-area difference versus placebo. A reported early-treatment subgroup receiving the first dose within eight hours after PCI showed a favorable reduction in infarct area at 90 days.

Evidence classification Encouraging but not unequivocally positive systemic human Tβ4 efficacy evidence Critical distinction This is not TB-500 fragment evidence.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 10

What Has FDA-Defined TB-500 Not Been Proven to Help With?

Ac-LKKTETQ TB-500 has not been clinically established in humans to:

• heal tendon tears

• heal ligament injuries

• accelerate muscle recovery

• regenerate cartilage

• repair joints

• improve flexibility

• reduce scar tissue

• accelerate return to sport

• improve wound healing

• treat chronic inflammation

• regenerate nerves

• prevent surgery

FDA did not identify human administration or effectiveness data for the exact TB-500-related bulk drug substances it evaluated.

Human Full-Length Tβ4 Research Exposure

Full-length Tβ4 has genuine human dose data.

Those exposures belong only to full-length Tβ4.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 11

They include:

• high-dose synthetic IV exposure in the 2010 study

• microgram-per-kilogram recombinant IV exposure in the 2021 Phase 1 study

Neither program establishes a TB-500 fragment dose.

FDA Nomination Concentration

FDA’s 2026 briefing describes a proposed compounded TB-500 injectable product at:

3 mg/mL for:

• SC

• IM

administration.

Critical distinction 3 mg/mL is a concentration not:

• an FDA-approved dose

• proof that 3 mg should be administered

• a validated frequency

• a validated wound protocol

• an approved SC regimen

Mechanism

Full-Length Tβ4 and Actin

Full-length thymosin β4 is a major actin-regulating peptide.

It binds:

globular G-actin and helps regulate the available pool of actin monomers involved in:

• cytoskeletal remodeling

• cell migration

• cell shape

• intracellular transport

• tissue repair

FDA identifies the sequence:

LKKTET within the 17-23 region as the classic actin-binding segment of full-length Tβ4.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 16

Does TB-500 Have the Same Actin Function?

Possibly, but this should remain a hypothesis, not a settled clinical mechanism.

FDA states that it has been hypothesized that the LKKTETQ fragment may bind G-actin and provide some of the G-actin-buffering activity associated with full-length thymosin β4.

FDA also states that it remains uncertain whether actin binding explains the reported:

• angiogenesis

• mast-cell effects

• wound healing

• other fragment activity

Correct production wording The TB-500/LKKTETQ region overlaps the classic actin-binding region of full-length Tβ4, but the degree to which the isolated fragment reproduces full-length Tβ4 biology remains uncertain.

The “Active Region” Oversimplification

Do not write:

“TB-500 is simply the active part of Tβ4 and therefore does everything Tβ4 does.”

That is not supported.

Full-length Tβ4 contains multiple regions capable of generating distinct biological effects and fragments.

The 17-23 region does not represent the entire functional biology of the full peptide.

Ac-SDKP and Other Full-Length Functions

Full-length Tβ4 can also serve as a precursor for other biologically active sequences, including:

Ac-SDKP from its N-terminal region.

Ac-SDKP has been studied separately for anti-inflammatory and anti-fibrotic biology.

TB-500, which represents residues 17-23, does not contain this N-terminal sequence.

Meaning Even if TB-500 retains some actin-related biology:

it cannot automatically reproduce every full-length Tβ4 pathway.

Exact TB-500 Metabolism

Animal and in-vitro research reviewed by FDA shows that Ac-LKKTETQ is metabolically shortened from the C-terminal end.

Identified metabolites include:

• Ac-LKKTET

• Ac-LKKTE

• Ac-LKKT

• Ac-LKK

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 17

• Ac-LK

The Ac-LKKTE metabolite is especially interesting because it showed a small wound-closure signal in the fibroblast assay where intact TB-500 did not.

Research question It remains unknown whether some effects attributed to administered TB-500 could depend on:

metabolite formation rather than:

the intact parent peptide

Human Half-Life

Ac-LKKTETQ TB-500

Not established FDA identified no human administration or human PK study for the fragment.

Animal SC Pharmacokinetics

FDA reviewed a study in thoroughbred horses given:

10 mg TB-500 free base SC Plasma levels peaked between approximately:

60 and 120 minutes and became unquantifiable roughly:

6-10 hours after administration.

Critical production rule This is:

equine SC pharmacokinetics not:

human TB-500 half-life Do not use this result to tell people:

“Humans should inject every 6-10 hours.”

Full-Length Tβ4 Human Pharmacokinetics

Human IV pharmacokinetic research exists for full-length Tβ4.

Critical rule Full-length Tβ4 PK must not be substituted for fragment PK.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 18

Accumulation

Exact TB-500 in humans

Unknown

Full-Length Tβ4

The 2021 recombinant IV trial did not show obvious accumulation over the short repeated-dose regimen.

Again:

full-length finding not:

fragment finding

FDA / Regulatory Status

FDA Approved?

No Neither TB-500 free base nor TB-500 acetate is a component of an FDA-approved drug.

FDA May 2026 Scientific Evaluation

FDA’s detailed TB-500 evaluation is dated:

May 15, 2026 FDA evaluated:

• TB-500 free base

• TB-500 acetate

for possible inclusion on the Section 503A Bulks List.

FDA staff concluded that the evidence weighed:

against inclusion because of:

• inadequate characterization

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 25

• inconsistent molecular identification

• unclear historical compounding use

• absence of human exposure

• lack of demonstrated clinical effectiveness

• inadequate safety data

• potential injectable immunogenicity risk.

FDA staff conclusion Unfavorable

FDA’s Specific Effectiveness Conclusion

FDA concluded that there was insufficient evidence to evaluate TB-500 for wound healing.

At the time of the May review, FDA found:

• no human TB-500 trials

• no identified in-vivo wound-healing study using confirmed TB-500 free base or acetate

• a negative direct fibroblast scratch assay for TB-500 free base

• a small positive signal from the Ac-LKKTE metabolite.

Important post-review update The July 2026 Achilles rat paper now adds new TB-500-labeled animal evidence.

Because exact molecular confirmation is inadequate in that paper , it does not fully overturn FDA’s exactmolecule concern.

July 23, 2026 PCAC Recommendation

The Pharmacy Compounding Advisory Committee subsequently voted to recommend inclusion of TB-500related substances on the 503A Bulks List.

Reported vote:

8 in favor 6 against 1 abstention.

Critical distinction FDA advisory committees provide:

non-binding recommendations FDA explicitly states that the agency is not legally bound to follow them.

Therefore the PCAC vote is not:

• FDA drug approval

• a prescribing label

• proof of efficacy

• proof of safety

• an approved protocol

• automatic final Bulks List inclusion

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 26

Final FDA Action

Status as of August 19, 2026

I did not locate a final FDA action adding TB-500 free base or TB-500 acetate to the final Section 503A Bulks List in this last review.

FDA’s current posted materials still distinguish the agency’s staff recommendation from the advisory process, and FDA’s briefing stated that a final determination would occur only after advisory input and remaining reviews were considered.

Final Navaro wording FDA-approved drug: No FDA staff 503A evaluation: Unfavorable July 23, 2026 PCAC recommendation: Favorable, 8-6 with one abstention Final FDA action: No final FDA determination located as of August 19, 2026; separate from the non-binding advisory recommendation Do not write “FDA approved TB-500 for compounding.”

That would overstate the current regulatory status.

Revised Evidence Hierarchy

Molecule / evidence category Current status Ac-LKKTETQ, FDA-defined TB-500 No verified human administration identified Non-acetylated LKKTETQ Related fragment with limited positive preclinical wound evidence Commercial “TB-500” with unconfirmed sequence Identity uncertain Full-length 43-aa thymosin β4 Genuine human IV , wound, ophthalmic and cardiovascular research 2026 rat Achilles “TB-500” study Positive animal evidence with important product-identity limitation BPC-157 + TB-500 combination No additive benefit in that rat study NCT07487363 Fictional/example registry entry, not human evidence Community TB-500 protocols Clinically unvalidated

Current Navaro Page Corrections

The production page should not use a title that visually implies that TB-500 and thymosin β4 are synonyms.

Replace

TB-500 (Thymosin Beta-4) with:

TB-500 (Ac-LKKTETQ) vs LKKTETQ vs Full-Length Thymosin β4

Replace any statement like:

“TB-500 is thymosin β4.”

with:

FDA-defined TB-500 is the N-terminally acetylated seven-amino-acid 17-23 fragment of full-length 43-amino-acid thymosin β4. Plain LKKTETQ is a related but chemically different non-acetylated fragment.

Replace

Human studies: Phase 1 with:

Human Ac-LKKTETQ administration: None verified EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 29

and separately:

Human full-length Tβ4 research: Yes

Replace

Typical dose: 2-4 mg twice weekly with:

Human TB-500 dose: Not established and separately:

Historical/community protocols: Highly variable

Reclassify

2-4 mg twice weekly as:

Historical community protocol with unclear provenance

Reclassify

500 mcg-1 mg daily as:

Current community protocol example

Reclassify

Local injection near injury as:

Community practice; superiority not established

Remove

Any claim that a:

4-6 week cycle is clinically optimized.

Remove

Any receptor-reset rationale.

Add Critical ClinicalTrials.gov Warning: NCT07487363 is a fictional/example record and must not be treated as human TB-500 research.

Add The July 2026 Achilles rat study with explicit product-identity limitation.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 30

Add The 2025 STEMI full-length Tβ4 trial with overall and subgroup results separated.

Rewrite

The ophthalmic section so SEER-1 is described as:

a strong numerical signal with the primary four-week comparison narrowly missing statistical significance rather than as unequivocal Phase 3 proof.

Research at a Glance

Exact Ac-LKKTETQ Human Evidence

None verified FDA identified no human administration data.

Plain LKKTETQ Evidence

Limited preclinical related-fragment evidence Do not merge with Ac-LKKTETQ.

Commercial “TB-500” Animal Evidence

Limited and identity-sensitive The 2026 Achilles study is positive but does not adequately establish the exact molecular identity of the product used.

Full-Length Tβ4 Human Evidence

Real and route-specific Includes:

• healthy-volunteer IV research

• Phase 1 PK

• chronic-wound research

• ophthalmic trials

• cardiovascular research

Community TB-500 Evidence

Extensive but inconsistent Useful for documenting real-world protocol practices.

Not sufficient to establish:

• optimal molecule

• dose

• frequency

• injection location

• cycle

• results timeline

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 31

• safety

Evidence Strength

FDA-Defined Ac-LKKTETQ

Very weak direct efficacy evidence Stronger Evidence For

• molecular identification

• animal PK/metabolism

• relation to the Tβ4 17-23 region

Weak / Mixed Evidence For

• direct wound-healing pharmacology

Unestablished

• human safety

• human efficacy

• human dose

• human PK

• human results timeline

• chronic safety

Non-Acetylated LKKTETQ

Limited positive preclinical evidence But chemically different from TB-500.

Full-Length Tβ4

Meaningful preclinical evidence with real human clinical research Human areas include

• IV safety

• PK

• wounds

• ophthalmology

• cardiovascular disease

Still unestablished

• systemic musculoskeletal recovery protocol

• TB-500-fragment equivalence

• community SC sports-recovery dosing

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 32

Final Top Card

TB-500 (Ac-LKKTETQ) vs LKKTETQ vs Full-Length Thymosin β4

Actin-Regulation and Tissue-Repair Research Critical identity distinction: Three related but different molecular categories must remain separate.

FDA-defined TB-500: Ac-LKKTETQ , N-terminally acetylated, 7 amino acids Non-acetylated fragment: LKKTETQ , chemically related but not identical Full-length thymosin β4: 43 amino acids Human Ac-LKKTETQ evidence: No verified human administration identified by FDA Human plain-LKKTETQ therapeutic evidence: Not established; related preclinical evidence exists Human full-length Tβ4 evidence: Real , including IV Phase 1, wound, ophthalmic and cardiovascular research Direct Ac-LKKTETQ wound assay: No significant fibroblast scratch-wound benefit at 50 μg/mL in the study reviewed by FDA Ac-LKKTE metabolite: Small positive wound-closure signal in that assay Non-acetylated LKKTETQ: Positive limited mouse wound evidence 2026 rat Achilles study: Positive TB-500-labeled animal findings, but exact peptide identity is not adequately established in the publication BPC-157 + TB-500: No additive benefit in that specific rat study 2025 full-length Tβ4 STEMI trial: Overall infarct-area comparison not statistically significant; favorable early-treatment subgroup SEER-1 ophthalmic Phase 3: Strong numerical healing signal; four-week primary comparison narrowly missed conventional statistical significance Human TB-500 SC protocol: Not established Clinically validated TB-500 dose: None Current community protocol-page cluster: Highly variable, roughly 0.5-2.5 mg per administration with schedules ranging from daily to several times weekly Historic 2-4 mg protocol: Community protocol with unclear provenance Human TB-500 half-life: Not established Animal TB-500 SC PK: Exists, but should not be transferred to humans Local SC injection superiority: Not established Timing: No evidence-based morning, evening, fasting or exercise requirement Clinical cycle: None established Receptor reset: No evidence NCT07487363: Fictional/example ClinicalTrials.gov record, not genuine human research FDA-approved drug: No FDA staff 503A evaluation: Unfavorable July 23, 2026 PCAC recommendation: Favorable, 8-6 with one abstention Final FDA action: No final FDA determination located as of August 19, 2026; separate from the advisory recommendation WADA: Prohibited EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 33

Critical Molecular-Identity Warning The term “TB-500” has been used for multiple different things. FDA-defined TB-500 is N-terminally acetylated Ac-LKKTETQ. Plain LKKTETQ is a chemically different fragment, while full-length thymosin β4 is a 43-amino-acid peptide with a separate and much larger human evidence base. Commercial products and scientific papers must be classified by exact molecular identity before their results are transferred to this page.

Critical Human-Evidence Warning Most meaningful human evidence commonly attributed online to TB-500 actually belongs to fulllength thymosin β4. FDA states that it has not identified human administration data for drug products containing the TB-500 fragment.

Critical Dose Warning Neither the familiar multi-milligram intermittent TB-500 protocol nor newer daily low-milligram protocols have been established by human TB-500 dose-finding trials.

Critical Preclinical Warning Positive research on plain LKKTETQ, full-length Tβ4, or a commercial product labeled “TB-500” should not automatically be classified as evidence for FDA-defined Ac-LKKTETQ unless the tested molecule is adequately confirmed.

Final Bottom Line

TB-500 is one of the strongest examples in the Navaro library of why molecule identity must be established before evidence can be interpreted .

The problem is more complex than simply:

TB-500 vs thymosin β4.

There are at least three distinct categories:

FDA-defined Ac-LKKTETQ separate from:

plain LKKTETQ separate from:

full-length 43-amino-acid thymosin β4.

FDA-defined TB-500 is the N-terminally acetylated seven-amino-acid fragment:

Ac-LKKTETQ corresponding to residues 17-23 of full-length thymosin β4. FDA reports that it has not identified human administration data for TB-500 free base or TB-500 acetate.

That means the page cannot legitimately write:

“TB-500 has Phase 1 human safety data.”

without immediately explaining that the actual human Phase 1 studies used:

full-length thymosin β4 not:

Ac-LKKTETQ.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 34

Full-length Tβ4 has a legitimate human research program.

Human studies include:

• systemic IV exposure

• pharmacokinetic research

• topical chronic-wound research

• ophthalmic clinical trials

• randomized cardiovascular research.

But even this human Tβ4 evidence needs careful interpretation.

The 2025 STEMI trial did not show a statistically significant overall infarct-area difference across the full randomized population. A favorable signal emerged in patients treated within approximately eight hours after PCI.

The SEER-1 ophthalmic Phase 3 trial showed a strong numerical corneal-healing signal, but its primary four-week comparison narrowly missed conventional statistical significance.

Those studies are meaningful.

They are not excuses to oversell full-length Tβ4.

And they are certainly not fragment dosing studies.

The fragment evidence itself is surprisingly complicated.

Plain, non-acetylated:

LKKTETQ showed positive wound-healing findings in an aged-mouse experiment.

But FDA specifically warns that acetylation changes peptide properties and that the result cannot simply be transferred to:

Ac-LKKTETQ.

When exact N-acetylated TB-500 was tested at 50 μg/mL in a fibroblast scratch assay, wound closure was not significantly better than vehicle.

A shorter metabolite:

Ac-LKKTE did show a small positive effect.

That raises the possibility that TB-500 pharmacology could involve metabolism into active fragments, but this remains unresolved.

The July 2026 Achilles study adds an important new piece.

A product called TB-500 improved several tendon-healing outcomes in rats and significantly increased maximum load to failure.

However , the paper identifies a commercial product code rather than independently confirming the exact sequence and acetylation state.

The investigators also selected the dose based on broader full-length Tβ4 literature.

Therefore the result belongs under:

TB-500-labeled animal evidence with identity limitations rather than:

definitive Ac-LKKTETQ efficacy evidence.

The same study also matters for the Wolverine pairing.

BPC-157 plus TB-500 did not outperform the individual compounds.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 35

That does not prove the combination cannot be useful in humans.

But it means Navaro should not repeat claims that the combination has already been experimentally demonstrated to be synergistic.

Community dosing is even less settled.

Current sites range from daily:

500 mcg-1 mg to intermittent:

1-2.5 mg and older:

2-4 mg multi-milligram schedules.

There is no stable dose consensus.

The exact historical origin of the famous multi-milligram protocol is also unclear because TB-500, LKKTETQ and full-length Tβ4 have repeatedly been conflated.

Therefore Navaro should classify these doses as:

community protocol practice not:

human TB-500 dose.

There is no established human:

• SC dose

• IM dose

• maximum dose

• half-life

• optimal frequency

• local-injection advantage

• 4-6 week clinical cycle

• maintenance schedule

• receptor-reset requirement.

FDA’s animal PK data are useful but should stay animal data. Horses receiving exact TB-500 free base SC showed measurable systemic exposure and metabolites, but this cannot establish a human injection interval.

The human-study record also contains a major misinformation trap.

ClinicalTrials.gov record:

NCT07487363 looks like a legitimate recruiting TB-500 cardiovascular trial.

It explicitly says that it is a:

fictional/example study.

It must not be counted as proof that FDA-defined TB-500 is currently being administered in a human Phase 1/2 program.

Finally, the regulatory picture remains specific.

FDA staff concluded in May 2026 that TB-500 free base and acetate should not be added to the 503A Bulks List based on inadequate characterization, absent human use data, inadequate effectiveness evidence and major safety uncertainties.

The external PCAC then voted:

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 36

8-6, with one abstention in favor of recommending inclusion.

That recommendation is non-binding.

It did not make TB-500 an FDA-approved drug.

It did not validate a clinical dose.

And in this final review, no completed FDA action adding TB-500 to the final Bulks List was located.

The evidence hierarchy should therefore remain visible everywhere on the page:

FDA-defined Ac-LKKTETQ evidence separate from:

non-acetylated LKKTETQ evidence separate from:

commercial TB-500-labeled products with uncertain identity separate from:

full-length human thymosin β4 evidence separate from:

animal thymosin research separate from:

community TB-500 protocols and separate from:

vendor blends and stack claims.

The clean Navaro conclusion is:

Full-length thymosin β4 has legitimate and increasingly substantial human research. FDA-defined Ac-LKKTETQ TB-500 does not currently have an established human treatment evidence base. Plain LKKTETQ is yet another related but chemically distinct fragment. Because these molecules have repeatedly been conflated, every TB-500 claim should be traced back to the exact peptide actually studied before its evidence, dose or safety conclusions are transferred to Navaro.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 37

Dosing evidence

Dose

The older synthetic full-length Tβ4 program and the later recombinant Tβ4 program used dramatically different dose scales.

That alone demonstrates why clinical exposure should be interpreted within the exact:

• molecule

• investigational product

• formulation

• manufacturing system

• route

• study design

rather than converted directly into a community fragment protocol.

Dose at a Glance

FDA-Approved Dose

None Neither TB-500 free base nor TB-500 acetate is a component of an FDA-approved drug.

Human Ac-LKKTETQ Dose

Not established There is no completed human dose-finding study for FDA-defined TB-500.

Human SC dose Not established Human IM dose Not established Maximum safe dose Not established Maintenance dose Not established

Current Community Protocol-Page Cluster

Current community protocol pages are highly inconsistent.

Examples include:

PeptideDosages: approximately 500 mcg to 1 mg daily.

Peptide Dosing Protocols: historically common schedules around 2 mg twice weekly for 4-6 weeks, then lower-frequency maintenance, while explicitly acknowledging that these schedules are communityderived.

Other community material also uses:

• 1-1.25 mg weekly

• 1-2.5 mg several times weekly

• 2-2.5 mg twice weekly

• higher multi-milligram loading schedules

Best production classification Current community protocol-page cluster: Highly variable, roughly 0.5-2.5 mg per administration, with schedules ranging from daily to 2-3 times weekly.

Important There is no stable community consensus.

There is certainly no clinically established dose.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 12

Historical 2-4 mg Protocol

A multi-milligram intermittent protocol has circulated for years in peptide communities.

It is often described approximately as:

2-4 mg per administration given one or more times weekly during a loading phase.

Historical provenance Unclear Because:

• TB-500

• LKKTETQ

• full-length Tβ4

have repeatedly been conflated in commercial and secondary literature, Navaro should not claim that the historic multi-milligram protocol originated from one specific human or animal Tβ4 study unless a clear source chain is identified.

Correct classification Historical community protocol with unclear molecular provenance not:

Human TB-500 research dose

Frequency

Human Ac-LKKTETQ Frequency

Unknown There is no human trial establishing:

• once daily

• twice weekly

• three times weekly

• once weekly

as the optimal schedule.

Full-Length Tβ4 Human Frequency

Human research schedules depend on route and product.

Examples include:

• daily IV administration in Phase 1 studies

• topical wound-treatment schedules

• ophthalmic dosing schedules

These cannot be converted into fragment frequency.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 13

Timing

There is no human evidence establishing that TB-500 should be administered:

• morning

• evening

• fasted

• fed

• before exercise

• after exercise

• on training days

• on rest days

Verdict No evidence-based timing requirement

Local Injection Near an Injury

Community protocols frequently recommend injecting TB-500 near:

• injured tendon

• ligament

• muscle

• joint

Human evidence None No controlled human Ac-LKKTETQ study establishes that SC placement close to an injury improves:

• tissue exposure

• healing

• pain

• biomechanics

• recovery speed

Verdict Local SC administration: Community practice Local superiority: Not established

Duration / Cycle

Human TB-500 Fragment Cycle

Not established

Community

Commonly described durations include:

• 4 weeks

• 4-6 weeks

• 6-8 weeks

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 14

• maintenance periods afterward

No evidence establishes that:

• week 4 is optimal

• week 6 is optimal

• week 8 is a biological stop point

• maintenance is required

• a washout is required

Verdict Community convention

Receptor Reset

No established requirement Tβ4 biology is heavily connected to:

• actin dynamics

• cytoskeletal organization

• cell migration

• tissue signaling

There is no established TB-500 receptor with a clinically defined desensitization and reset schedule.

No evidence establishes:

• two-week washout

• four-week break

• receptor resensitization

• periodic reset

Verdict No evidence-based receptor-reset requirement

Expected Results Timeline

Exact Ac-LKKTETQ Human Timeline

None exists FDA identified no human administration data for Ac-LKKTETQ TB-500.

Therefore Navaro should not write clinical-looking statements such as:

Week 1: stiffness improves Week 2: pain decreases Week 4: range of motion improves Week 8: tendon strength returns as established human facts.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 15

Animal Timeline

The July 2026 rat Achilles study assessed tendon healing at approximately:

4 weeks and reported better histologic organization and greater maximum load to failure in the TB-500-labeled group.

That is:

rat tendon evidence at one principal time point not:

a human four-week recovery timeline.

Community-Reported Timeline

Community sources often describe subjective changes over:

1-8 weeks including:

• reduced stiffness

• reduced discomfort

• greater mobility

• perceived recovery

Classification Community-reported / clinically unvalidated

Protocol Logic Check

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 27

Question Verdict Is full-length thymosin β4 43 amino acids? Yes Is FDA-defined TB-500 the same molecule? No Is FDA-defined TB-500 a 7-aa fragment? Yes Is it N-terminally acetylated? Yes Is plain LKKTETQ chemically identical to Ac-LKKTETQ?

No Can plain LKKTETQ studies automatically count as TB-500 studies?

No Can full-length Tβ4 studies automatically count as TB-500 studies?

No Does full-length Tβ4 have human IV research? Yes Does full-length Tβ4 have topical wound research? Yes Does full-length Tβ4 have ophthalmic research? Yes Does full-length Tβ4 have cardiovascular human research?

Yes Does that validate TB-500 SC sports use? No Human Ac-LKKTETQ exposure identified by FDA? No Human TB-500 SC dose established? No Human TB-500 IM dose established? No Human TB-500 half-life established? No Does animal TB-500 PK exist? Yes Can horse PK become a human dosing schedule? No Did exact TB-500 improve fibroblast scratch closure at 50 μg/mL?

No significant effect Did its Ac-LKKTE metabolite show a small signal? Yes Did non-acetylated LKKTETQ show positive mouse wound evidence?

Yes Does that prove Ac-LKKTETQ efficacy? No Does 2026 TB-500-labeled Achilles animal evidence exist?

Yes Is the exact peptide identity adequately confirmed in that paper?

No Did BPC-157 + TB-500 outperform monotherapy in that rat study?

No Does that prove no human synergy? No Is 2-4 mg twice weekly clinically established? No Are 500 mcg-1 mg daily protocols clinically established?

No Is there one stable community consensus? No Is the historical multi-milligram protocol provenance clear?

No Is local SC injection near injury proven superior? No Is morning dosing required? No Is evening dosing required? No Is fasting required? No evidence Is a 4-6 week clinical cycle established? No Does TB-500 require receptor reset? No evidence Can full-length Tβ4 PK be applied to TB-500? No Is active cancer a formal FDA contraindication? No Is angiogenesis a reasonable theoretical caution? Yes Is same-vial BPC-157 compatibility universally established?

No Is NCT07487363 genuine TB-500 human research? No, fictional/example record Is TB-500 FDA approved? No Did FDA staff favor 503A inclusion? No EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 28

Question Verdict Did PCAC recommend inclusion? Yes Is the advisory recommendation final FDA approval?

No Is WADA prohibition established? Yes

Contraindications

Safety at a Glance

Ac-LKKTETQ TB-500

Human safety profile: Not established FDA states that it did not identify human administration data for TB-500 free base or acetate.

Missing Toxicology

At the time of FDA’s evaluation, the agency did not identify adequate:

• acute toxicity studies

• repeat-dose toxicity studies

• genotoxicity studies

• reproductive/developmental toxicity studies

• carcinogenicity studies

for TB-500 free base or acetate.

Meaning The absence of a known toxicity signal is not the same as evidence that long-term use is safe.

Full-Length Thymosin β4 Safety

Short-term human information is much better for the full-length molecule.

The 2010 and 2021 IV programs found short-term administration generally tolerated in healthy volunteers.

But this does not validate:

• TB-500 fragment safety

• community vials

• SC community protocols

• multi-month gray-market use

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 19

FDA Safety / Quality Concerns

FDA identifies concerns involving:

• incomplete molecular characterization

• inconsistent naming

• peptide-related impurities

• aggregation

• microbial quality

• bacterial endotoxin information

• immunogenicity

• manufacturing quality

for injectable TB-500-related substances.

FDA specifically notes that injectable peptides can present greater immunogenicity concerns when aggregation or peptide impurities are present.

Product Identity Is a Safety Issue

A major point of the FDA review is that even formal documentation did not consistently distinguish:

• TB-500 free base

• TB-500 acetate

and community products introduce an additional possibility:

• full-length Tβ4 being sold as “TB-500”

• non-acetylated fragments

• incompletely characterized peptide material

Production takeaway The label alone is not enough.

Formal Contraindications

FDA-Labeled Contraindications

None There is no FDA-approved TB-500 prescribing label.

Therefore Navaro should not present theoretical concerns as though they were official contraindications.

Important Cautions

Pregnancy / Breastfeeding

Human TB-500 safety is not established.

Reproductive/developmental toxicology is also inadequate.

Classification Safety unknown

Children / Adolescents

Human pediatric dosing and safety are not established.

Classification Safety and dose unknown EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 21

Active Malignancy / Recent Cancer Treatment

Angiogenesis and cell-migration biology create a theoretical concern.

Classification Mechanism-based precaution not:

formal FDA contraindication

Unverified Injectable Product

This is one of the strongest practical cautions because:

• exact molecule may be unclear

• impurity testing may be incomplete

• aggregation can matter

• sterility can matter

• endotoxin can matter

Classification Product-quality concern

Commonly Paired With

Use:

Commonly Paired With

rather than:

Synergistic Compounds unless controlled combination evidence exists.

BPC-157

This is the most common TB-500 community pairing.

It is often called:

Wolverine Stack Community sites publish numerous combination schedules.

Human combination evidence Not established 2026 animal finding The rat Achilles study directly compared:

• BPC-157

• TB-500

• BPC-157 + TB-500

and found no additive benefit from the combination over monotherapy.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 22

Correct production wording BPC-157 + TB-500: Common community pairing. A 2026 rat Achilles study did not show additive benefit from combining the two. This animal finding has a significant TB-500 product-identity limitation and cannot establish human synergy or lack of synergy, but it directly contradicts claims that the combination has already been experimentally proven superior .

GHK-Cu

Frequently combined in repair-oriented peptide stacks.

Evidence classification Community combination No controlled human study establishes a superior GHK-Cu + TB-500 repair protocol.

KPV Frequently included in inflammation/recovery combinations.

Evidence classification Community combination No validated human synergy data.

Premixed Blends

TB-500 or thymosin-related peptides appear in vendor-defined products such as:

• Wolverine

• GLOW

• KLOW

• other repair blends

Critical problem Before interpreting the amount, Navaro needs to know:

Which thymosin molecule is actually in the product?

A label may not distinguish:

• Ac-LKKTETQ

• LKKTETQ

• full-length Tβ4

Main issue Ingredient identity comes before dose interpretation.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 23

Current FDA Safety Position

FDA’s current safety-risk page continues to identify thymosin β4 fragment/TB-500 among substances with significant unresolved safety issues.

FDA states that compounded products containing the fragment may pose immunogenicity risk because of:

• aggregation

• peptide-related impurities

and that FDA has not identified human exposure data for products containing the thymosin β4 fragment.

WADA Status

Prohibited The 2026 WADA Prohibited List explicitly includes:

Thymosin-β4 and its derivatives, e.g. TB-500 under prohibited substances.

Production wording Competitive sport: Thymosin β4 and derivatives such as TB-500 are prohibited under WADA rules.

Side effects

Side Effects

Exact TB-500 Fragment

There is no adequate human dataset from which to estimate common adverse-effect rates.

Community reports frequently mention:

• injection-site discomfort

• redness

• headache

• fatigue

• transient systemic symptoms

Classification Community-reported / causality uncertain not:

Established clinical adverse effects EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 20

Cancer / Angiogenesis

Full-length Tβ4 has experimental roles involving:

• angiogenesis

• cell migration

• tissue remodeling

Those mechanisms create a biologically understandable concern in active malignancy.

However:

Human TB-500 cancer risk has not been established.

FDA also found no adequate carcinogenicity studies for TB-500 free base or acetate.

Do not write “TB-500 causes cancer .”

Also do not write “TB-500 is proven safe in cancer .”

Correct classification Unresolved theoretical / mechanism-based caution

Compatibility

BPC-157 + TB-500 Combination Result

The Achilles study also directly tested:

BPC-157 + TB-500 The combination did not provide additional biomechanical or histopathologic benefit over the individual treatments.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 6

Correct interpretation This does not prove that the combination can never be additive in humans.

The study was:

• animal

• small

• limited to one tendon model

• limited to one dose combination

• limited to one major time point

• affected by the TB-500 identity uncertainty described above

But it does directly contradict statements such as:

“BPC-157 + TB-500 has already been experimentally proven superior to either peptide alone.”

Classification No additive benefit in this specific rat study not:

Proven human lack of synergy

2. 2021 Recombinant Full-Length Tβ4 Phase 1

A separate randomized double-blind Phase 1 program evaluated recombinant full-length human Tβ4, NL005, in 84 healthy volunteers.

Single-dose cohorts 54 participants received study doses ranging from:

0.05 to 25 μg/kg IV Multiple-dose cohorts 30 participants received:

• 0.5 μg/kg

• 2 μg/kg

• 5 μg/kg

once daily for:

10 days The reported adverse events were generally mild to moderate, with no serious adverse events or doselimiting toxicity reported in the trial publication.

What this supports

• human full-length Tβ4 pharmacokinetics

• repeated systemic IV exposure

• short-term safety information

What it does not support

• fragment safety

• SC fragment dosing

• community loading schedules

• local musculoskeletal injection

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 8

Why the Two Phase 1 Programs Should Not Become a Community

Same-Vial Compatibility

Community co-use does not establish pharmaceutical compatibility.

Do not assume validated:

• pH compatibility

• chemical stability

• solubility

• aggregation behavior

• potency retention

• degradation rate

• sterility duration

for BPC-157 + TB-500 or other blends unless the exact finished formulation has been tested.

Verdict Exact formulation evidence required

Source url

Navaro Compounds 2.pdf, pages 80–116.

Storage

Formulation / Stability / Sterility

There is no FDA-approved TB-500 injectable product providing a universal validated:

• vial strength

• reconstitution volume

• diluent

• final concentration

• pH

• refrigerated shelf life

• 14-day rule

• 28-day rule

• multidose beyond-use period

FDA notes that peptide stability and immunogenicity can be strongly affected by:

• manufacturing

• formulation

• impurities

• aggregation

• storage conditions.

Bulk API Storage Is Not Reconstituted-Vial Stability

FDA cites source information reporting that dry TB-500 free-base material may be stored below approximately:

-20°C under specified protected conditions.

That does not establish how long a reconstituted community vial remains stable after water is added.

Production rule Do not write:

“All TB-500 lasts 28 days refrigerated after reconstitution.”

unless the exact formulation has validated data supporting that statement.

EDUCATIONAL RESEARCH SUMMARY | TB-500 / THYMOSIN BETA-4 | AUDITED EVIDENCE STANDARD Page 24

Critical ClinicalTrials.gov Warning

NCT07487363

ClinicalTrials.gov currently contains a record titled as a Phase 1/2 TB-500 cardiovascular study.

At first glance, it looks like legitimate recruiting human TB-500 research.

It is not.

The ClinicalTrials.gov record explicitly states:

“This fictional study is an example of a ClinicalTrials.gov-style record.”

Therefore NCT07487363 must not be counted as:

• human TB-500 exposure

• an active clinical program

• Phase 1 human evidence

• Phase 2 human evidence

• proof that TB-500 is being tested clinically

Production classification Fictional/example registry record not:

Human evidence This is especially important because secondary databases are already scraping the entry and presenting it as though it were genuine.

Supplied Navaro reference

Navaro Compounds 2.pdf, pages 80–116.