Repair claims

TB-500.

Often mentioned in the same breath as BPC-157 — and sharing the same core problem: lots of biological plausibility, essentially no human trials.

Repair claimsInvestigationalSourced profile
Read this first

This is educational information, not medical advice, and The Peptide University does not sell peptides, supplies, or supplements. Many compounds discussed here are sold as “research chemicals” and are not approved for human use outside of clinical trials. Laws vary by country, and nothing here is a recommendation to obtain or use anything. Talk to a qualified clinician about your own situation.

● Investigational — not approved for human use

The FDA classifies TB-500 as a Category 2 bulk drug substance (significant safety concerns; not permitted for compounding). WADA prohibits thymosin beta-4 and its derivatives, including TB-500. It is not approved for human use.

What it is

TB-500 is a synthetic fragment related to thymosin beta-4 (TB4), a naturally occurring protein involved in cell repair. A key nuance often glossed over: most published research is on the full TB4 protein, while what's sold online is a small synthetic piece of it — and a fragment doesn't automatically share the whole protein's effects or safety.

The claims

It's promoted for wound healing, reduced inflammation, and tissue regeneration. A scoping review notes biologic plausibility across several repair-related pathways — but plausibility is a starting point, not proof of clinical benefit.

The evidence

The honest summary from the literature: there are essentially no human clinical trials on TB-500 itself. A 2026 scoping review concluded the mapped literature does not establish clinical efficacy, optimal dosing, route of administration, product equivalence, or long-term safety for musculoskeletal uses. Some sources note small cohorts describing it as well-tolerated, but no large or long-term safety studies exist.

Safety

Its safety in humans is effectively unknown. “Well-tolerated in a handful of people” is not the same as an established safety profile, and the fragment-vs-whole-protein distinction adds further uncertainty. Long-term effects have not been characterized.

Regulatory status

FDA Category 2 bulk drug substance (safety concerns; not for compounding); WADA-prohibited; not approved for human use. Sold online as a research chemical.

FAQ

QIs TB-500 the same as thymosin beta-4?

Not exactly — it's a synthetic fragment associated with TB4. Research on the full protein shouldn't be assumed to transfer to the fragment sold online.

QIs it safe because it's 'well-tolerated'?

Those reports come from small, uncontrolled use. Absence of reported harm in a few people is not demonstrated safety, especially long-term.

QCan athletes use it?

No — it's on the WADA Prohibited List. Testing positive carries sanctions.

Sources

This profile summarizes the following. Follow the links to read the originals — and remember that summaries age, so check for newer information.

Inclusion here is not endorsement of any source's claims; several are cited so you can compare how different outlets characterize the same evidence.

Questions & comments

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