Healing & Recovery

TB-500

Also known as: Thymosin Beta-4, Tβ4

Molecular Identifiers

Molecular Formula

C36H66N10O13

CAS Number

476014-70-7

PubChem CID

10169788

Molecular Weight

846.97 Da

Overview

Synthetic fragment of Thymosin Beta-4, a 43-amino acid protein present in virtually all nucleated cells. Acts on G-actin sequestration, promoting cell migration, differentiation, and new blood vessel formation.

TB-500 draws clinical interest for its action in systemic tissue repair: by sequestering G-actin, it regulates the cytoskeleton and stimulates cell migration, angiogenesis (via VEGF), and stem cell differentiation at injury sites. Preclinical studies show improvement in healing of tendons, ligaments, skin, and mucosa, with an associated anti-inflammatory effect. It is frequently paired with BPC-157 in recovery protocols.

TB-500 has no regulatory approval in humans. It is most often prescribed through compounding pharmacies as off-label use, with typical loading protocols (5 mg twice weekly for about 4 weeks) followed by maintenance. WADA classifies thymosin beta-4 and its analogues as a substance prohibited in sports competition, and there are documented cases of misuse in racehorses.

Within regenerative peptides it is most often compared to BPC-157: while BPC-157 acts more locally and stands out on the gastrointestinal axis, TB-500 works via G-actin sequestration and cell migration, with a more systemic profile, a longer half-life, and less frequent dosing. Because their mechanisms are complementary, the two are commonly stacked in recovery protocols.

Sequence (1 letter): LKKTETQ
Extended notation: Leu-Lys-Lys-Thr-Glu-Thr-Gln

Half-life

~2-3 hours

Administration Route

Subcutaneous or intramuscular

Category

Healing & Recovery

Mechanism of Action

  • Sequestration of monomeric G-actin, regulating the cytoskeleton
  • Promotion of angiogenesis via VEGF upregulation
  • Reduction of inflammation through cytokine modulation
  • Promotion of cell migration (keratinocytes, endothelial cells)
  • Stem cell differentiation at injury sites

Dosage Protocol

Data compiled from the literature. This does not constitute medical advice.

Parameter Value
Dose 2-5 mg per injection
Frequency Twice per week
Timing Any time of day
Duration 4-8 weeks

Reported Side Effects

Adverse effects described in the literature. Severity and frequency vary between individuals.

  • Mild headache
  • Lethargy
  • Flushing at injection site
  • Nausea (rare)

Product Properties

Purity >99%
Appearance White lyophilized powder
Solubility Soluble in water
Source Solid-phase peptide synthesis (SPPS)
Storage Lyophilized: -20°C for up to 2 years, 2-8°C for up to 6 months. Reconstituted: 2-8°C for up to 4 weeks. Protect from light and moisture. Avoid repeated freeze-thaw cycles.

Presentations & Preparation

Vials of TB-500 found in the research market:

2 mg5 mg10 mg

Reconstitution

  • Diluent: Bacteriostatic water
  • Volume: 1-2 ml per 5 mg vial
  • Slowly inject along the vial wall
  • Wait for complete dissolution without shaking
  • Gently swirl if necessary

Storage

  • Lyophilized: Room temperature or refrigerated
  • Reconstituted: Refrigerated 2-8°C (up to 3-4 weeks)
  • Do not refreeze after reconstitution
  • Protect from light and excessive heat
Reconstitution Calculator

Scientific Studies

Published studies on TB-500.

2007 · Nature

Thymosin beta4 promotes blood vessel formation and stem cell migration

Smart N, Risebro CA, Melville AA, et al.
1999 · J Invest Dermatol

Thymosin β4 promotes dermal healing

Malinda KM, Sidhu GS, Mani H, et al.

Related Peptides

ARA-290

2-4 mg per injection · Once daily

BPC-157

250-500 mcg per injection · 1-2 times daily

Cartalax

1-2 capsules orally (0.2 g per capsule, containing AKS-4 peptide complex) · 1-2 times daily, with meals

GHK-Cu

1-3 mg per injection · Once daily or every other day

LL-37

50-200 mcg per injection · Once daily

MGF

200-400 mcg per injection · Once daily (MGF) or 2-3 times per week (PEG-MGF)