TB-500

In simple words

TB-500 is a short synthetic piece of the natural protein thymosin beta-4. It is studied for tissue recovery after sports injuries, but it has no human studies of its own — all data were obtained for the full protein.

What this molecule is

Ac-Leu-Lys-Lys-Thr-Glu-Thr-Gln — a synthetic fragment of the 17-23 region of Tβ4. ~888 Da. ≠ Full-length Tβ4 (43 aa).

Why it is studied

A synthetic Tβ4 fragment designed to reproduce its actin-binding activity. Popular in sports communities. No clinical studies of its own — all data relate to full-length Tβ4 (Phase I + Phase II RCTs). Practice: tissue regeneration after sports injuries.

How it works

LKKTETQ motif → G-actin binding → ↑cell migration to the injury. Partial angiogenesis and anti-inflammatory action (only via LKKTETQ, without the other Tβ4 domains).

Doses used in studies

Studies used 2-5 mg SC 2-3 times/week for a course of 4-6 weeks.

Combined with in studies

• BPC-157 — regenerative synergy
• GHK-Cu — matrix
• Ipamorelin — GH + regeneration

Level of evidence

Level D Cells and reviews. Only cell studies (in vitro), theory, or reviews. The earliest stage. no clinical data of its own

Studies in PubMed

1. A first-in-human, randomized, double-blind, single- and multiple-dose, phase I study of recombinant human thymosin β4 in healthy Chinese volunteers. (J Cell Mol Med, 2021)
2. Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. (Cornea, 2015)
3. Thymosin beta4 and cardiac repair. (Ann N Y Acad Sci, 2010)
4. Thymosin β4: A Multi-Faceted Tissue Repair Stimulating Protein in Heart Injury. (Curr Med Chem, 2020)
5. Utilizing Developmentally Essential Secreted Peptides Such as Thymosin Beta-4 to Remind the Adult Organs of Their Embryonic State-New Directions in Anti-Aging Regenerative Therapies. (Cells, 2021)
6. Thymosin β4 and prothymosin α promote cardiac regeneration post-ischaemic injury in mice. (Cardiovasc Res, 2023)