TB-500 is one of the most requested compounds in repair-pathway research, and one of the most misunderstood — starting with what the vial actually contains. This overview covers the molecule, how it relates to full-length thymosin β4, and how to evaluate a lot before study.
What TB-500 is
Thymosin β4 (Tβ4) is a 43-residue actin-sequestering protein found in nearly all mammalian cells and studied extensively in wound-repair, angiogenesis, and cell-migration models. TB-500 refers to the synthetic active fragment centered on Tβ4’s actin-binding domain — commonly the acetylated segment Ac-LKKTETQ (~890 Da) — rather than the full protein. Research suppliers also offer full-length material; the certificate of analysis tells you which one you actually have, which is why the observed mass matters so much on this compound.
Where it appears in research
TB-500 features in in vitro models of cell migration, actin dynamics, and tissue remodeling, and is very frequently studied alongside BPC-157 — the pairing is common enough that dual research blends exist, and both appear together in the KLOW quad blend with GHK-Cu and KPV.
Stability and handling
- Lyophilized: stable refrigerated/frozen away from light and humidity; −20°C for long-term storage.
- Reconstituted: dissolve gently in bacteriostatic water for laboratory use; refrigerate and avoid freeze-thaw cycling.
Lot quality checklist
- Identity: the certificate’s observed mass should match the fragment (~890 Da for Ac-LKKTETQ) — a value near 4,960 Da means you have full-length Tβ4 instead.
- Purity: ≥99% by HPLC with the method stated (HPLC vs MS, explained).
- Traceability: the vial’s lot number should retrieve a public certificate — every Heartland lot lives in the COA portal.
Research availability
TB-500 research material (10mg) ships lyophilized with per-lot HPLC purity and mass-spec identity, same-day from Tulsa, Oklahoma.
TB-500 is supplied strictly for in vitro laboratory research — not for human or veterinary use.