TB-500 (Thymosin Beta-4 fragment)

Muscle/RecoveryThymosin β4 fragment / researchExperimental

Usually sold as an acetylated thymosin-β4 actin-binding fragment (LKKTETQ), not full-length Tβ4. Not FDA-approved. Related to prohibited thymosin-β4 use in sport.

Calculate Dose

For research use only.

Key Facts

CAS: 77591-33-4
Molecular Weight (MW): ~889 Da (heptapeptide fragment forms vary)
Half-life: Hours; not well defined for research fragments
Unit: mg
Administration Route: Subcutaneous
Frequency: 1–2× weekly or divided micro-doses
Last updated: 8/23/2026
Targets: G-actinCell migration pathways

Overview

Usually sold as an acetylated thymosin-β4 actin-binding fragment (LKKTETQ), not full-length Tβ4. Not FDA-approved. Related to prohibited thymosin-β4 use in sport.

Protocol

Dosage Range: 5–10 mg total per week (divided)
Frequency: 1–2× weekly or divided micro-doses
Cycle: 4–8+ weeks or as-needed maintenance
Administration Route: Subcutaneous
Reconstitution Guide: Add 2–5 mL bacteriostatic water per vial as preferred concentration.

Science

Mechanism of Action

The LKKTETQ motif mediates actin binding and is associated with cell migration and angiogenesis in thymosin-β4 biology. Commercial TB-500 is a fragment, not the full 43-aa hormone.