HomePeptides › TB-500

TB-500

Thymosin Beta-4 fragment

Tier 4 · Preclinical Only
Class
Synthetic peptide fragment
Molecular target
G-actin binding
Sequence / structure
Fragment containing the actin-binding motif LKKTETQ
Evidence tier
Tier 4 — Preclinical Only
Category
Tissue Repair & Cytoprotection

Biology & mechanism

Thymosin Beta-4 is a 43-amino-acid actin-sequestering protein present in most cells. TB-500 is a synthetic fragment retaining the LKKTETQ actin-binding motif. By regulating G-actin availability it influences cell migration — the proposed basis for effects on angiogenesis, keratinocyte migration, and wound repair. Note that TB-500 and full-length Thymosin Beta-4 are frequently conflated in marketing; they are not the same molecule and the research literature largely concerns the full-length protein.

What the research actually shows

Full-length Thymosin Beta-4 reached clinical trials for dry eye and dermal wounds and did not reach approval. Preclinical models report cardiac, corneal, and dermal repair effects. Human evidence for the TB-500 fragment specifically is essentially absent.

Regulatory status

Not FDA-approved. Was subject to FDA 503A bulk substance review; nomination withdrawn April 2026 without Category 1 placement. Prohibited in sport (WADA S0).

Safety signals

No meaningful long-term human safety data. Shares the pro-angiogenesis theoretical concern raised for BPC-157.

No usage guidance is published here

Forge Bioenergy does not publish dosing, reconstitution, or administration protocols for any peptide. See our editorial policy for why. If you are considering any substance on this page, that conversation belongs with a licensed physician.

References & further reading

Regulatory status changes. This page reflects our reading of public sources as of July 2026 and should be independently verified before it is relied upon.

Important notice Forge Bioenergy publishes scientific reference information only. Nothing on this site is medical advice, a therapeutic claim, or a recommendation to use any substance in humans. Many peptides described here are not approved by the FDA for any use, and several are approved only for narrow indications under prescription. We do not publish dosing, administration, or usage protocols. Consult a licensed physician before making any medical decision.