TB4
The full-length 43 amino acid protein that TB-500 is derived from. Naturally occurring in most tissues; mechanistically it sequesters G-actin and has been reported to promote keratinocyte and endothelial migration and angiogenesis.
Regulatory status (as of Sept 2026)
Not FDA-approved for any indication. The related fragment TB-500 was recommended by PCAC for the 503A Bulks List on July 23, 2026 (advisory); it awaits FDA rulemaking and was not lawfully compoundable under 503A as of Sept 17, 2026. Full-length thymosin beta-4 is prohibited in sport under WADA.
See the FDA peptide regulatory tracker · Read our July 27, 2026 dispatch on the FDA PCAC peptide vote2 studies referenced · Last reviewed Oct 1, 2026 · Reviewed by The Peptide Dispatch Editorial Team · How we research & label content
Thymosin Beta-4 is an investigational compound tested in mid-stage (phase 2) human trials. The full-length 43 amino acid protein that TB-500 is derived from.
| Half-life | Not established in published research |
|---|---|
| How it's given in studies | Subcutaneous injection |
| Research stage | Phase 2 |
| Dosing | Published research: Topical 0.01-0.03% gel in a double-blind placebo-controlled dose-escalation phase 2 study of 73 patients with… detailsTopical 0.01-0.03% gel in a double-blind placebo-controlled dose-escalation phase 2 study of 73 patients with venous stasis ulcers (0.03% was the most effective dose); phase 2 dermal work also covers pressure ulcers and epidermolysis bullosa wounds. No published subcutaneous systemic dosing in humans.Community-reportedCommunity-reported: 750 mcg - 2 mg, subcutaneous injection |
Published-research dosing is what was given in the cited studies (species and units as reported). Community-reported dosing is what users describe, not from clinical studies. Neither is a recommendation. Not medical advice.
Where each point comes from: Clinicalhuman trials and FDA labels Lab / animalrodent, cell and ex vivo studies Community-reporteduser experience and commonly used protocols, not from clinical studies
In plain terms: It is a natural protein that helps cells move and is thought to support healing, based mostly on preclinical work. Sequesters G-actin. Proposed to promote keratinocyte and endothelial cell migration, with angiogenic and anti-inflammatory activity reported in preclinical work (review, Kleinman 2016); a phase 2 RCT in venous ulcers suggested that one dose may have the potential to accelerate healing (Guarnera 2010).
How to read this: Each item below is an effect observed in research subjects in the cited studies — think of Dexter, our stand-in research subject. These are findings from the literature, not results you should expect, and not medical advice.
Community-reportedIn user communities, Thymosin Beta-4 is typically run at 750 mcg - 2 mg (subcutaneous injection). This is not a recommendation.
Side effects reported in studies are listed separately below.
Community reports are anecdotal, vary widely in product quality and purity, and are not medical advice. Talk to a licensed provider.
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| Peptide | Half-Life | Route | Research Status |
|---|---|---|---|
| Thymosin Beta-4 | Unknown | Subcutaneous injection | Phase 2 |
| ARA-290 (Cibinetide) | No published PK data found | Subcutaneous injection, Intravenous | Phase 2 |
| BPC-157 | Elimination t1/2 < 30 min (rats and beagle dogs, IV and IM); IM bioavailability ~14-19% rats, 45-51% dogs | Subcutaneous injection | Preclinical (animal) |
| Copper Peptide AHK-Cu | Topical (not systemically relevant) | Topical | In vitro only |
| GHK-Cu | No published PK data found | Subcutaneous or topical | Cosmetic/topical |
Values reflect figures reported in published research. Compare any peptides side-by-side →
This peptide belongs to the Healing category. View All Healing Peptides
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Dosing, half-life figures, and mechanism descriptions on this page are compiled from peer-reviewed published research, with the species and study type stated where reported. Figures labeled “Dosing used in published research” describe what was given in those studies and do not constitute dosing recommendations for any human use. Each cited paper is listed with DOI and PubMed links in the References section above. Found an error? Contact us.