TB-500

A fragment of thymosin beta-4, a peptide found naturally in injured tissue — the 'foreman' of the healing stacks.

⚠ Safety first — read this before anything else on this page

Approval status: TB-500 is not FDA-approved for any use. FDA reviewers stated they identified no human exposure data for this fragment at all. As of November 2026 it sits inside the same draft enforcement-discretion policy as BPC-157 — discretion is not approval.

What has actually happened to people:

Almost nothing compound-specific is on record — and that is the record. The one FDA adverse-event report naming TB-500 involved a blended BPC-157/TB-500 product labeled 'research purposes only': the user developed diffuse skin darkening and gum darkening (FDA advisory-committee briefing, July 2026).
FDA's stated concerns for TB-500 are immunogenicity — an immune reaction driven by the peptide aggregating — based on its chemistry, not on human cases, because there are no human cases in the literature to count.

What nobody knows: No response of any human body to TB-500 has ever been published. Its entire human safety profile — effects, interactions, long-term outcomes — is unknown. The human literature sellers cite is for full-length thymosin beta-4, a different substance.

Get medical care now if:

Swelling of the lips or tongue, or trouble breathing, after an injection — call emergency services.
An injection site that gets redder, hotter, or more painful over days instead of better.
A new lump or sore at an injection site appearing one to several weeks later — the delayed infection pattern; it needs a clinician, and standard antibiotics may fail on the organisms involved.

Who should stay away: Anyone with a cancer history — TB-500 promotes cell migration and blood-vessel growth, the same theoretical tumor question raised for BPC-157, on even thinner evidence. Also: minors, anyone pregnant, and tested athletes — TB-500 is prohibited in sport (WADA).

The product problem: The full-length protein TB-500 is cut from, thymosin beta-4, was among the falsified products in a Belgian public-health lab study of seized internet-pharmacy peptides (Janvier et al., Talanta, 2018): two-thirds of the products tested were below 95% purity and about 30% carried incorrect amino-acid sequences.

Talk to a doctor who knows you are taking it. See our doctors directory. If you were harmed, report it to FDA MedWatch — your report is how the record gets built.

We don't publish doses, protocols, or sources — for any compound, ever. Our Legal Mandate.

What it is

A fragment of thymosin beta-4, a peptide found naturally in injured tissue — the ‘foreman’ of the healing stacks.

What creators claim

Dr. Froese describes TB-500 as controlling actin — the scaffolding cells use to move and rebuild — helping healing cells migrate faster and supporting new blood-vessel formation. It is the second half of the Wolverine stack and appears in GLOW and KLOW.

What the evidence shows

There are zero human trials of the TB-500 fragment. The evidence base is preclinical and mechanistic extrapolation from thymosin beta-4 biology.

Forms it is discussed in

Injectable is the form discussed by creators; it is marketed almost entirely through the research-chemical channel.

Dangers on record

Because it promotes cell migration and blood-vessel growth, the same theoretical angiogenesis cautions raised for BPC-157 are raised for TB-500 by critics. Human safety data is essentially absent — that absence is itself the danger page’s headline. See Dangers.

Legal status (as of November 7, 2026)

Not FDA-approved. Same policy path as BPC-157: off Category 2 (April 2026), PCAC 8–6 for the Bulks List (July 2026), not on the list, and one of the six in the October 30 enforcement-discretion policy (acetate, single-ingredient, conditions). Banned in sport (WADA S2).