Verified July 2026 · Cited to primary sources

TB-500: Evidence Grade DAnimal studies only, unproven in humans.

Grade DUnder FDA reviewSafety: amber

The honest verdict

TB-500 is not FDA-approved and is under FDA review (July 23, 2026 PCAC). Human evidence is Grade D — the fragment sold to consumers has animal data only. The full-length Tβ4 human trials are a different molecule.

TB-500 at a glance

Class
Synthetic actin-binding peptide fragment (~7-aa active fragment of Tβ4)
Mechanism
Regulates actin and promotes cell migration, angiogenesis and wound healing — marketed for soft-tissue and tendon recovery.
Also known as
Thymosin Beta-4 fragment, TB4 fragment
Research applications
  • Soft-tissue and tendon/ligament recovery (preclinical)
  • Wound healing (full-length Tβ4, a different molecule, reached human Phase 2)
Forms
subcutaneous injection
Legal status
Under FDA review
WADA (anti-doping)
Prohibited (S2 — Tβ4 and its derivatives explicitly named)
Evidence grade
Grade DAnimal studies only, unproven in humans

How we grade evidence

Every grade is assigned by a fixed A–F rubric — human-trial strength, not hype or affiliate status. Last verified July 6, 2026.

What is TB-500?

The other half of the "wolverine stack" — soft-tissue recovery claims, but only animal data for the fragment actually sold.

Regulates actin and promotes cell migration, angiogenesis and wound healing — marketed for soft-tissue and tendon recovery.

How strong is the evidence for TB-500?

Grade D: animal/preclinical only for the TB-500 fragment, no human RCT (rule 5 fired). Note: full-length Thymosin β-4 reached human Phase 2 via RegeneRx — but that is a different molecule from the TB-500 fragment sold to consumers.

Primary sources (3)

  1. FDA PCAC July 23–24, 2026 meeting (docket)
  2. Federal Register FDA-2025-N-6895 (April 2026 503A reclassification)
  3. WADA Prohibited List (S2 — growth factors, Tβ4 explicitly named)

What is TB-500 used for?

TB-500 is marketed for the goals below. See how it ranks against other peptides in each — by evidence, not hype.

What does TB-500 cost — and how do you access it legally?

Typical cost

UNKNOWN (usually bundled with BPC-157 courses, ~$350–$900)

No verified standalone clinic price. Commonly bundled with BPC-157 recovery courses; we mark the standalone number UNKNOWN rather than guess.

No legal supervised access route right now.

TB-500 has no compliant US route today while its compounding status is under FDA review. Vials sold "for research use only" are a gray-market fig-leaf, not a legal loophole — we don't link them. If you pursue TB-500, do it with a licensed clinician, and re-check its legal status first.

Is TB-500safe? Side effects & risks

Limited human safety data, no major documented harms

No human safety data for the fragment. Theoretical tumor-promotion via angiogenesis. Gray-market contamination. WADA-prohibited (S2).

Medical disclaimer: This page is independent editorial information, not medical advice, and Best Peptide For That is not a medical provider. We do not provide dosing. Talk to a licensed clinician before starting, stopping, or changing any peptide or medication. Full medical disclaimer.

FAQ

TB-500 FAQ

Is TB-500 the same as Thymosin Beta-4?

Not exactly. TB-500 is a short synthetic fragment marketed as a Tβ4 stand-in. Full-length Thymosin β-4 reached human Phase 2 trials, but the fragment sold as TB-500 has only animal data — an important distinction the marketing blurs.

Is TB-500 FDA approved or legal?

No. TB-500 is not FDA-approved and has no legal supervised US route today. It was removed from 503A Category 2 in April 2026 and is on the July 23, 2026 PCAC docket.

Is the BPC-157 + TB-500 "wolverine stack" proven?

No. Both are Grade D — animal studies only. The stack is a community protocol, not something validated in human trials. We don't provide dosing for it.

Compare TB-500 with…

Head-to-head evidence-grade matchups people weigh against TB-500.

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