TB-500 (Thymosin Beta-4)

Overview

TB-500 is a synthetic version of thymosin beta-4, a naturally occurring 43-amino-acid protein involved in tissue repair, wound healing, and blood vessel formation. It works primarily by sequestering G-actin monomers, which promotes cell migration and angiogenesis at injury sites, and it also dampens inflammation. That combination of repair signaling and anti-inflammatory action is why it is studied for tendon, ligament, and muscle recovery. Its estimated half-life is roughly two hours with around 60% subcutaneous bioavailability, which in research contexts typically translates to multiple doses per week. The honest caveat is that human pharmacokinetic data is thin. Most of the supporting evidence comes from animal models and in vitro work, and TB-500 is not an approved medication.

Pharmacokinetic summary

Model tier

Simple (t½ + F, Tmax estimated)

Half-life

0.1 days

Bioavailability

60%

Typical dose

0.25–2.5 mg