Verified July 2026 · Cited to primary sources
TB-500: Evidence Grade D. Animal studies only, unproven in humans.
The other half of the "wolverine stack." Soft-tissue recovery claims, but only animal data for the fragment actually sold.
The honest verdict
TB-500 is not FDA-approved and is not yet legal to compound. On July 23, 2026 the FDA's PCAC panel voted 8 to 6 (1 abstention) to recommend adding it to the 503A list for wound healing, overriding the FDA's own scientists, but the FDA still decides and has not acted. Human evidence stays 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 comes from a fixed A to F rubric: human-trial strength, not hype or affiliate status. Last verified July 6, 2026.
What is TB-500?
Compound class: Synthetic actin-binding peptide fragment (~7-aa active fragment of Tβ4)
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 (4)
Is TB-500 legal? (Status July 2026)
Regulatory limbo; the July 2026 PCAC panel has advised, the FDA decision is pending.
July 2026 PCAC vote
On July 23, 2026 the FDA's Pharmacy Compounding Advisory Committee voted to recommend adding TB-500 to the 503A compounding list (8 to 6, with 1 abstention), overriding the FDA's own scientists. That is an advisory recommendation, not legalization: the FDA still makes the final decision and has not acted, so TB-500 is not yet legally compoundable. Track the FDA peptide vote →
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 to $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, so we don't link them. If you pursue TB-500, do it with a licensed clinician, and re-check its legal status first.
Telehealth programs do advertise several compounds in this position as prescribable online. We checked those advertised menus against the law in peptide telehealth programs.
Is TB-500safe? Side effects & risks
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.
Free tool
Peptide reconstitution calculator
Enter the mg in the vial and the ml of bacteriostatic water, and get the concentration plus the units to draw on an insulin syringe. It does the arithmetic on your numbers, and it never suggests a dose. See all four calculators.
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. That distinction matters, and the marketing blurs it.
Is TB-500 FDA approved or legal?
No. TB-500 is not FDA-approved and has no legal supervised US route today. On July 23, 2026 the PCAC panel voted 8 to 6 (1 abstention) to recommend adding it to the 503A compounding list, but that is an advisory recommendation to the FDA, not legalization. The FDA has not acted yet.
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.
From our portfolio
Tracking TB-500?
Titrate is an iOS app for logging doses, schedules and progress over time, with a reconstitution calculator built in. It tracks, it does not prescribe.
Compare TB-500 with…
Head-to-head evidence-grade matchups people weigh against TB-500.
Keep reading
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Grade BSermorelin
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