LTP·01learntopeptide
Healing & repairEvidence C3 cited

Thymosin Beta-4

aka Tβ4 · TB4 · thymosin β4 · prothymosin

Thymosin Beta-4 is known for its role in tissue repair and regeneration, making it valuable for recovery.

Molecular wt
4963g/mol
Formula
C212H350N56O78S
CAS
77591-33-4
Half-life
4 h
estimated
Tmax
2 h
Route
Subcutaneous injection
PubChem
45382195

Sequence

One-letter43 residues

SDKPDMAEIEKFDKSKLKKTETQEKNPLPSKETIEQEKQAGES

Three-letter

Ac-Ser-Asp-Lys-Pro-Asp-Met-Ala-Glu-Ile-Glu-Lys-Phe-Asp-Lys-Ser-Lys-Leu-Lys-Lys-Thr-Glu-Thr-Gln-Glu-Lys-Asn-Pro-Leu-Pro-Ser-Lys-Glu-Thr-Ile-Glu-Gln-Glu-Lys-Gln-Ala-Gly-Glu-Ser-OH

Read this before quoting the sequence
Full-length thymosin beta-4 is the 43-residue N-acetylated peptide above (UniProt P62328 residues 2-44; INN timbetasin). TB-500, as sold and discussed in the peptide market, is NOT the same molecule: it is generally the synthetic 7-residue actin-binding fragment Tbeta4(17-23), LKKTETQ (often N-acetylated), i.e. about one sixth of the protein. The MW, formula, CAS and CID in this record apply to full-length Tbeta4 only and must not be attached to TB-500. TB-500 is listed separately by name on the WADA Prohibited List, which reflects that they are treated as distinct substances.
Source ↗

Mechanism of action

Thymosin Beta-4 promotes tissue repair by modulating actin dynamics, which is crucial for cell migration and wound healing. It also reduces inflammation by downregulating pro-inflammatory cytokines. Additionally, it enhances angiogenesis, the formation of new blood vessels, which supports tissue regeneration. Thymosin Beta-4 also has anti-apoptotic properties, protecting cells from programmed cell death during stress.

What the evidence actually shows

Grade C

There are limited human trials on Thymosin Beta-4, primarily focusing on its effects on wound healing and tissue repair. These studies suggest potential benefits, but the sample sizes are small and more research is needed to confirm efficacy and safety. The majority of evidence comes from animal and in vitro studies.

Regulatory status

Status
Not approved anywhere. No Drugs@FDA record and no DailyMed SPL.
Clinical stage
Phase 3. RGN-259 (0.1% Tbeta4 ophthalmic solution) has completed phase 3 dry-eye trials ARISE-2 (NCT02974907) and ARISE-3 (NCT03937882) and is in the recruiting phase 3 neurotrophic keratopathy trial SEER (NCT05555589). Systemic (injectable) Tbeta4 has only reached phase 1/2.
WADA
Prohibited at all times. Both 'thymosin-beta4' and 'TB-500' are named explicitly under S2.3 (Growth Factors and Growth Factor Modulators) of the WADA 2026 Prohibited List.
Source ↗

Pharmacokinetics

Half-life
4 h
Tmax
2 h
Absorption
subcutaneous
Elimination
renal
Washout
3 days
Low-confidence pharmacokinetics
These figures are recorded as estimated rather than measured in a published PK study. Treat them as an order of magnitude. Anything downstream of them — accumulation, steady state, washout — inherits that uncertainty.

Dosing — what backs each figure

Full-length thymosin beta-4 has real human trial dosing, but only as topical formulations (0.1% ophthalmic solution 4-6x daily; 0.01-0.1% gel once daily for wounds) and as microgram/kg intravenous infusions in acute-MI trials in China. There is no established human subcutaneous dose and no approval anywhere, so any 'mg twice weekly' injection protocol circulating for this compound is community convention rather than trial-derived.

ClinicalApproved labelling or a published human trial
No established human dose
No approved label or completed human trial establishes a dosing regimen for this compound. Anything presented as a standard protocol for it — anywhere — is someone's convention rather than a finding.

Handling and storage

No compound-specific stability data exists
No approved product exists in any jurisdiction, so there is no authoritative storage specification. The clinical material studied (RGN-259) is a 0.1% ophthalmic solution, not a reconstituted injectable, and its storage conditions are not published in the trial reports located. No compound-specific stability data found. Ported storage text ('-20C ~24 months lyophilised; 2-8C ~4 weeks reconstituted') is generic peptide-handling boilerplate that was applied identically across many compounds in this dataset. It is not sourced to this compound. General peptide handling still applies — reconstitute gently, keep it cold, keep it dark — but any specific figure you see quoted for this compound elsewhere is someone's assumption, not a measurement.
→ Reconstitution walkthrough→ Reconstitution calculator

Safety

References (3)

Data provenance

Chemistry and citations on this page were checked against primary sources on 2026-08-14. Values that could not be verified were left blank rather than filled with a plausible guess.

Could not verify
storage.lyophilized, storage.reconstituted, storage.lightSensitive, reconstitution.solvent

Research use only
This profile is educational reference material. It is not medical advice, not a prescription, and not an endorsement of self-administration. Compounds discussed here are research chemicals and most are not approved for human therapeutic use.

Related in Healing & repair

BPC-157
A synthetic pentadecapeptide derived from a protein found in gastric juice. Studied for tissue repair, tendon/ligament healing, and gut protection in preclinical models.
BPC-157 Arginate
BPC-157 Arginate is the arginine salt form of Body Protection Compound 157, a synthetic pentadecapeptide derived from a partial sequence of human gastric juice protein. This formulation pairs the BPC-157 peptide with arginine as a counter-ion, which proponents claim provides improved stability and enhanced oral bioavailability compared to the standard acetate salt form. The underlying peptide consists of 15 amino acids and has demonstrated cytoprotective, anti-inflammatory, and tissue-healing properties across numerous preclinical studies. It promotes angiogenesis, modulates nitric oxide pathways, and upregulates growth factor expression. The arginate form is marketed as offering better gastric survival and systemic absorption when taken orally, though direct head-to-head comparative data remains limited.
GV1001
A 16-amino acid peptide derived from the active site of human telomerase reverse transcriptase (hTERT). Originally developed as a cancer immunotherapy vaccine, now investigated for anti-inflammatory and anti-aging properties.