A synthetic fragment of Thymosin Beta-4, an actin-regulating peptide, researched for tissue repair, wound healing and regeneration.
Research use only — no marketing approval for systemic human use. Note that 'TB-500' (a lab fragment) is not identical to the full-length thymosin beta-4 used in clinical trials. Banned in sport by WADA since 2018 as a growth factor.
Also known as: Thymosin Beta-4, Tβ4, RGN-259 / RGN-352 (clinical formulations)
Sequesters G-actin to maintain a ready pool for rapid actin polymerisation, building the lamellipodia/filopodia that drive cell migration. This speeds migration of fibroblasts, keratinocytes, endothelial and stem cells to injury sites, promotes angiogenesis, upregulates laminin-5 and dampens inflammatory signalling during repair.
The strongest human data are ophthalmic, using the full peptide as eye drops — not injectable TB-500. Small phase 2 dry-eye trials showed significant reductions in corneal staining and discomfort, and a randomised, double-masked phase 3 in neurotrophic keratopathy reported improved corneal healing. In contrast, the systemic injectable use it is actually sold for — tendon, muscle and cardiac repair — rests on animal models. Ophthalmic promise does not transfer to the injected product.
We report both positive and negative trial results. For exact study protocols, read the sources — we cite them rather than repackage them.
Bars reflect the strength & volume of research evidence for each use — not a guarantee of results.
Topical ocular formulations were generally well tolerated. Systemic injectable TB-500 has essentially uncharacterised human safety; theoretical concerns about promoting angiogenesis (relevant to tumour growth) are raised but unresolved.
BPC-157 — the standard marketing pairing, on claimed complementary tissue-repair and angiogenic effects. GHK-Cu — grouped under 'regeneration'. None of these combinations has controlled human trial support.
Mechanistic context only — we don't publish combinations, amounts or protocols.
Versus BPC-157, thymosin beta-4 actually has a real clinical trial record — but only for eye-surface disease with a topical drug, not for the injected systemic healing claims that mirror BPC-157's marketing.
No — a key misconception. The clinical evidence is for full-length thymosin beta-4 eye drops, not the injected fragment sold to athletes.
Not demonstrated in humans. Cardiac benefit is preclinical/animal stage only.
Its growth-factor activity on tissue regeneration is exactly why WADA prohibits it, regardless of proven benefit.
No reviews yet. If you've used TB-500, be the first to share what it helped with and any side effects.
⚠️ Educational research information only — not medical advice. Many peptides are sold strictly for laboratory research and are not approved treatments. The evidence scores reflect research interest and strength, not efficacy or safety for any individual. Always consult a qualified professional.