§ Research summary · Regenerative

TB-500 10 mg

Also known as · Thymosin β-4 · Tβ4 · Timbetasin

Regenerative·1 min read·reviewed 2026-05-07

Synthetic full-length 43-residue thymosin β-4. The most abundant intracellular actin-sequestering peptide in mammalian tissues.

Chemistry quick-facts

CAS
77591-33-4
Formula
C212H350N56O78S
MW
4963.4 Da
Length
43 aa
Status
Limited clinical evidence. Thymosin β-4 has been investigated in Phase 2 trials for dry-eye disease (RGN-259), pressure ulcers, and epidermolysis bullosa. No approval for therapeutic use.
Purity (HPLC)
≥ 99.1%

Mechanism of action

G-actin sequestration → cytoskeletal dynamics. Secondary: integrin-linked kinase upregulation, laminin-5 expression modulation.

Research context

TB-500 denotes synthetic thymosin β-4 (Tβ4), a naturally occurring 43-amino-acid peptide. It is among the most abundant intracellular proteins, functioning primarily as a G-actin sequestering molecule that regulates actin polymerisation and cell motility.

RegeneRx Biopharmaceuticals has developed synthetic Tβ4 under the code RGN-259 through Phase 2 trials in dry-eye disease and neurotrophic keratopathy.

Published studies

A non-exhaustive list of peer-reviewed studies referenced when curating this entry. Click through to the primary source for the full text.

  1. Goldstein AL, Hannappel E, Sosne G, Kleinman HK (2012). Thymosin β4: a multi-functional regenerative peptide. Expert Opinion on Biological Therapy.
  2. Sosne G, Ousler GW (2015). Thymosin beta 4 ophthalmic solution for dry eye — Phase 2. Clinical Ophthalmology.

Active clinical trials

  • NCT02623244Phase 3 · Completed

    ARISE-3: RGN-259 in dry eye

Reconstitution

Solvent
Bacteriostatic water for injection (0.9% benzyl alcohol) — included with kit
Typical volume
1 – 2 mL
  • · Inject diluent slowly down the side of the vial onto the cake.
  • · Swirl gently — do not shake.
  • · Solution should be clear and colourless. Discard if not.

Storage

Lyophilised
−20 °C, desiccated, protected from light. Stable at 15–25 °C for up to 30 days in transit.
Reconstituted
2–8 °C, original vial, consumed within 4 weeks.
Shelf life — sealed
24 months from date of manufacture when stored lyophilised at −20 °C.

FAQ

Is this the same as the short Ac-SDKP tetrapeptide?+

No. Full 43-residue Tβ4. Ac-SDKP (goralatide) is a separate N-terminal tetrapeptide with distinct activity.

Research-use disclaimer

This page summarises the research literature on TB-500 10 mg for in vitro laboratory investigation only. It is not medical advice, not a treatment recommendation, and not a substitute for a qualified physician. Material is sold for analytical chemistry and cell-culture research, not for human or veterinary administration.

View TB-500 10 mg in the catalogue →
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