TB-500 has direct animal evidence, but we did not identify verified human treatment trials for the TB-500 fragment itself. Human injury-recovery claims, dosing and long-term safety therefore remain unestablished.
Still uncertain: Whether it improves injury recovery in people, human dosing, how the body handles it, long-term safety or comparative benefit.
By confirming your subscription, you agree to receive occasional WhichPeps Evidence Updates. Kit processes the signup and email delivery for WhichPeps. Privacy. Unsubscribe anytime.
What does the evidence mean in simple terms? table
What is it?
Synthetic fragment of thymosin beta-4
Entity type
Peptide
Research focus
Wound/tissue-repair research claims
Human evidence
FDA reports no identified human drug-product exposure for the TB-500 fragment. A 2026 rat Achilles-tendon study provides animal evidence for a material the authors call TB-500, but the inspected paper does not independently establish that it was the FDA-defined LKKTETQ fragment. A fictional/example registry record is not counted as human evidence.
Regulatory status
Not FDA-approved; FDA has reviewed TB-500-related substances in the compounding context and highlights safety/data gaps.
Main limitations
Human injury-recovery efficacy, human dosing, pharmacokinetics, long-term safety or comparative benefit.
Safety
Potential immunogenicity and peptide-related impurities; safety of human administration is not established.
Evidence reviewed
2026-09-18
i
No verified human drug-product exposure or therapeutic outcome dataset for the TB-500 fragment was identified. A 2026 rat Achilles-tendon study provides animal evidence for a material the authors call TB-500; exact LKKTETQ fragment identity is not independently established by the inspected paper. A ClinicalTrials.gov-style TB-500 record encountered during research explicitly states that it is fictional/example cont…
Outcome-level evidence
Evidence is not one score.
Each record below answers a narrower question about an outcome, population or context. Evidence status and the study finding are shown separately so strong evidence is not mistaken for a positive effect.
Finding: Human efficacy and safety remain unestablished.
Uncertainty / evidence gap: A ClinicalTrials.gov record NCT07487363 must NOT be counted: the record itself explicitly states it is a fictional/example study.
Finding: The animal study reports effects for a material labelled TB-500; exact LKKTETQ fragment identity is not independently established by the inspected publication.
Uncertainty / evidence gap: Animal results do not establish human tendon healing, and the exact material identity remains a separate verification question.
Evidence rule: an outcome-specific evidence label is not a recommendation, a safety rating or an overall score for the compound.
Evidence synthesis
✓No direct human efficacy or safety evidence for commercial TB-500 fragment use was identified.
✓Human efficacy and safety remain unestablished.
✓The animal study reports effects for a material labelled TB-500; exact LKKTETQ fragment identity is not independently established by the inspected publication.
Important limitations
!Online claims frequently conflate the fragment with full-length thymosin beta-4.
!No verified human therapeutic study/outcome dataset identified.
!Small animal study; short follow-up; animal route/dose are not a human protocol.
Selected study & evidence records
FDA evidence audit: TB-500 (thymosin beta-4 fragment LKKTETQ) human exposure
2026 · Regulatory evidence review / no human exposure identified
FDA states it has not identified human exposure data for drug products containing the TB-500 fragment.
Potential immunogenicity and peptide-related impurities; safety of human administration is not established.
Human adverse effects, pharmacokinetics and long-term safety are not established; FDA highlights potential immunogenicity, aggregation and peptide-impurity concerns.
Technical details
Mechanism / biologyMarketed TB-500 is understood by FDA as a seven-amino-acid thymosin beta-4 fragment; biological claims are often extrapolated from full-length thymosin beta-4.
Route / formulation boundaryTB-500 fragment evidence must remain separate from full-length thymosin beta-4 and from fictional/example registry content.
Identity / data-quality noteDo not count NCT07487363 as human evidence; the registry record identifies itself as fictional/example content.
Study / label regimen evidenceStudy-regimen evidence reviewed. No direct human drug-exposure regimen identified. FDA states it has not identified human drug-product exposure data for the TB-500 fragment.
WhichPeps does not rely on a single headline study when the evidence base is broader. Primary research, registries, regulators and supporting records are kept distinct.
2structured study records
3outcome records
6linked source records
How to read these counts: they show evidence coverage, not evidence strength. One large, well-designed study can be more informative than several weak or indirect records.
Show supporting and discovery sources
Study pages above contain the records used for public evidence summaries. The links below include supporting, regulatory and literature-discovery sources; a registry or search result is not treated as proof of benefit.
FDA source ↗ — Supports the evidence summary; read full paper before quoting exact endpoints.
Evidence rule: WhichPeps keeps human, animal, laboratory, regulatory and product/formulation evidence distinct. Common names help people find the page; they do not change the underlying scientific identity.
