TB-500
Also known as Thymosin Beta-4 fragment, TB4
A synthetic peptide related to thymosin beta-4, studied for cell migration and tissue repair.
Medically reviewed by Dr. Jonathan Snipes, MD
Reviewed for clinical accuracy · Last reviewed July 22, 2026 · Review policy
Quick answer
TB-500 is a synthetic peptide related to thymosin beta-4, a naturally occurring protein involved in cell migration and tissue repair. The parent peptide reached early human trials for wound and cardiac repair, but TB-500 itself is not FDA-approved, is prohibited in sport, and is under FDA compounding review at the July 2026 PCAC meeting.
- Type
- Synthetic thymosin beta-4 fragment
- FDA status
- Not approved; compounding under review
- Human evidence
- Early trials of parent peptide (TB4)
- Evidence grade
- C (Emerging Human Data)
- Banned in sport
- Yes (WADA)
Key takeaways
- →TB-500 is marketed as a research version of thymosin beta-4 (TB4), a natural peptide central to cell migration and wound healing.
- →TB4 (the parent peptide) reached early-phase human trials for wound, cardiac and corneal repair, which is why we grade the class C (Emerging Human Data) rather than D.
- →TB-500 the fragment is less directly studied in humans than TB4, and it is not FDA-approved.
- →It is prohibited in sport under WADA, and its compounding status was under FDA review at the July 2026 PCAC meeting.
- →As with BPC-157, the biggest practical risk is the unregulated research-chemical supply, where purity and dosing are unverified.
TB-500 is usually discussed alongside BPC-157 as a recovery peptide, but its evidence story is slightly different and worth separating carefully. TB-500 is a synthetic peptide related to thymosin beta-4 (TB4), a naturally occurring protein that plays a real, well-documented role in cell migration and tissue repair. The nuance is that most of the human research applies to TB4, not to the specific TB-500 fragment sold in the peptide market.
How TB-500 works
Thymosin beta-4 regulates actin, a protein essential to cell movement, which lets cells migrate to sites of injury and supports angiogenesis and tissue remodeling. TB-500 is intended to reproduce the active region of TB4. The underlying biology is legitimate and studied; the open question is how faithfully the synthetic fragment reproduces it in humans, and at what dose and safety profile.
What the evidence shows, by use
Each use is graded on the same A-E scale, based on human-trial quality rather than popularity.
Wound and tissue healing
CEmerging Human DataThymosin beta-4 reached early-phase human trials for wound healing; evidence for the TB-500 fragment specifically is thinner and largely preclinical.
Cardiac and corneal repair
CEmerging Human DataTB4 has been investigated in early human and animal studies for cardiac and corneal repair; results are preliminary, not confirmatory.
Athletic injury recovery
EAnecdotalPopular for this use based on user reports, but there is no controlled human trial supporting TB-500 for sports injury recovery.
Dosing
There is no FDA-approved TB-500 product and no validated human dosing. Protocols in circulation are derived from animal work and community practice. Given that most market supply is research-grade material of unverified purity, any use should be through a licensed clinician and legitimate pharmacy rather than research-chemical vendors.
Side effects
- •Injection-site reactions · Reported
- •Fatigue or lethargy · Reported
- •Head-rush or lightheadedness · Reported
- •Temporary flu-like feelings · Reported
Legal & regulatory status
TB-500 is not FDA-approved, is prohibited in sport, and its compounding pathway was under FDA review at the July 2026 PCAC meeting.
Is TB-500legal? Full regulatory status →Where to get it: TeleRanked independently ranks the telehealth providers that offer clinician-prescribed peptides. See our Peptide Therapy rankings. We rank providers, we do not sell compounds, and rankings are never for sale.
Frequently asked questions
Is TB-500 the same as thymosin beta-4?+
Not exactly. TB-500 is a synthetic peptide meant to reproduce the active region of thymosin beta-4 (TB4). Most human research applies to TB4, not the specific TB-500 fragment.
Is TB-500 FDA-approved?+
No. TB-500 is not FDA-approved, and its compounding status was under FDA review at the July 2026 PCAC meeting.
Is TB-500 banned in sport?+
Yes. TB-500 is prohibited under the WADA framework.
How we grade evidence
Grade C: Emerging Human Data. Early or small human studies exist; results are preliminary and not yet confirmed at scale. Our A-E scale reflects the strength of human evidence, not how popular a compound is.
Sources
- 1.July 23-24, 2026: Meeting of the Pharmacy Compounding Advisory Committee · U.S. Food & Drug Administration
- 2.WADA Prohibited List · World Anti-Doping Agency
- 3.Compounding and the FDA: Questions and Answers · U.S. Food & Drug Administration