Peptides
TB-500
What is it?
TB-500 usually means a seven-amino-acid fragment of thymosin beta-4, a longer peptide involved in cell movement. Some sellers use the name for different substances, so the exact identity matters. It is not an FDA-approved medicine. [1]
How might it work?
The fragment includes a region associated with actin binding and cell movement. Work on full-length thymosin beta-4 suggests possible roles in wound repair and inflammation, but a result with that 43-amino-acid peptide cannot be assumed to apply to a seven-amino-acid TB-500 product. [1,2]
Why do people use it for recovery?
The recovery interest is understandable: a controlled human study of topical, full-length thymosin beta-4 in venous ulcers suggested some wound-healing potential. That was a different molecule, route, and type of wound from the injected TB-500 sold for sports injuries. FDA's 2026 review did not identify a human TB-500 trial for wound healing. This leaves a promising biological idea, not a measured recovery benefit for the marketed fragment. [1,2]
What should you know before considering it?
Product naming and purity are important here. FDA raised concerns about inconsistent identity and possible immune reactions or peptide impurities with injectable products. Athletes subject to anti-doping rules should check the current prohibited list before considering it. [1]
PRACTICE EXAMPLE
How much?
FORM & SCHEDULE
What it refers to
by injection twice a week for 4–6 weeks
No approved TB-500 dose exists. Product identity and injection purity are important, and competitive athletes must check anti-doping rules.
2–2.5 mg — TB-500 by injection twice weekly for four to six weeks is a protocol described by peptide educator Jay Campbell, not a tested effective dose for the seven-amino-acid fragment. His account is useful for understanding common practice, but cannot establish benefit or safety. [3]
Read detailed dosing notes
The specific molecule on the label matters; full-length thymosin beta-4 research does not validate this amount. There is no FDA-approved TB-500 dosing schedule. [1]
Sources & further reading
- FDA (2026). TB-500-related bulk drug substances briefing (opens in a new tab)www.fda.gov
- Findley et al. (2010). The effect of thymosin treatment of venous ulcers (opens in a new tab)pubmed.ncbi.nlm.nih.gov
- Jay Campbell (2026). TB-500 peptide: benefits, dosage and side effects (opens in a new tab)jaycampbell.com