TB-500

The parent protein Thymosin beta-4 has been studied in human trials for wound healing and dry eye, but TB-500 is a different molecule: FDA defines it as the acetylated seven-amino-acid fragment Ac-LKKTETQ, and states that because acetylation irreversibly alters charge, hydrophobicity and size, results for the non-acetylated heptapeptide cannot be extrapolated to it. FDA has not identified any human exposure data on TB-500 by any route. In animals, the one controlled healing study of TB-500 we found, in rats after Achilles tendon repair (Biçer et al. 2026), reported repaired tendons that held significantly more force than the control group's; the authors call it exploratory. FDA reports zero FAERS adverse-event reports for it through 26 March 2025, which FDA itself footnotes as a reflection of how little anyone reports, not as evidence of safety.

TB-500 is a lab-made seven-amino-acid fragment of Thymosin Beta-4 (amino acids 17–23, with an acetyl cap), not the whole protein. Thymosin Beta-4 has 43 amino acids and is found in almost every cell; it was first isolated from calf thymus. Protocols treat it as working through the whole body, unlike BPC-157, so they do not tie the injection site to the injury. That idea comes from its parent protein and from animal and lab work; it has not been tested for TB-500 in people. It is used for soft tissue injury, multiple injury sites, and post-surgical recovery.

Read the molecule before the mechanism. TB-500 is the acetylated seven-amino-acid fragment Ac-LKKTETQ, residues 17–23 of the 43-amino-acid parent, Thymosin Beta-4. Everything that follows is Thymosin Beta-4's pharmacology, and FDA states that acetylation irreversibly alters charge, hydrophobicity and size, so results for the parent cannot be extrapolated to TB-500. The mechanism below is inherited by argument, not demonstrated for this compound. Thymosin Beta-4 is the main G-actin sequestering peptide in cells. Actin is the scaffolding protein that gives a cell its shape and lets it crawl; by binding free actin monomers, it regulates that scaffolding and therefore controls cell shape, motility and division. The practical result, in lab and animal studies, is that repair cells migrate toward wound sites. It upregulates migration across several cell types at once: keratinocytes, endothelial cells, stem cells. It also reduces inflammatory markers and has shown anti-fibrotic properties, meaning less scar tissue laid down during healing. TB-500 carries the stretch of the parent that binds actin. FDA says it remains to be determined whether that binding explains any healing effect, and in the one cell-culture test of TB-500 itself, it did not close scratch wounds in cultured cells.

• Loading2–2.5 mg

  Twice per week

  Weeks 1–4 on our peptide page; the recovery guide describes a 4–6 week loading phase. Totals roughly 4–5 mg per week.

• Maintenance2–2.5 mg

  Once per week

  Weeks 5 onward. Protocols allow any injection site, on the view that TB-500 acts through the whole body.

• Wolverine Stack total2–5 mg

  Per week, split into 2–3 injections

  The figure our BPC-157/TB-500 page gives when the two are run together.

• Community 0.5 mg0.5 mg

  Twice per week

• Community 1 mg1 mg

  Twice per week

• Community 1.5 mg1.5 mg

  Twice per week

1. 1
   Week 1–2

   Subtle. Reduced inflammation and mild pain reduction are the commonly described early signals.

2. 2
   Week 2–3

   Our recovery guide places initial noticeable change here, later than BPC-157, and reads that as a body-wide rather than local effect.

3. 3
   Week 4–6

   Loading phase completes. Functional improvement in soft tissue injuries; the dosing schedule drops to weekly.

4. 4
   Week 6–8

   Our recovery guide describes significant improvement in this window for TB-500 run solo.

Absence from this list does NOT mean safety. It means lack of research.

Storage

Lyophilized powder: refrigerator 2–8°C for several months, freezer −20°C for 1–2+ years. Reconstituted with bacteriostatic water: refrigerate and discard after 28 days. Never freeze reconstituted solution. Swirl, never shake.

Cost

$80–$120 per 4–6 week cycle (two 5 mg vials)

1. 1
   Goldstein et al., 2005 · Thymosin beta4: a multi-functional regenerative peptide, Expert Opin Biol Ther 5(1)

   PMID 16099219Source
2. 2
   Sosne et al., 2010 · Biological activities of thymosin beta4, FASEB J 24(7)

   Source
3. 3
   Malinda et al., 1999 · Thymosin beta4 accelerates wound healing, J Invest Dermatol 113(3)

   Source
4. 4
   FDA · TB-500 briefing document for the Pharmacy Compounding Advisory Committee, 15 May 2026: the acetylated 17–23 fragment and its actin-binding region; thymosin beta-4 first isolated from calf thymus and expressed in almost every cell type; the in-vitro scratch test (Rahaman 2024) and horse pharmacokinetics (Ho 2012); FAERS searched through 26 March 2025

   Source
5. 5
   Lee & Padgett, 2021 · Intra-Articular Injection of BPC 157 for Multiple Types of Knee Pain

   PMID 34324435
6. 6
   Biçer et al., 2026 · Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: A histopathological and biomechanical study, Jt Dis Relat Surg 37(3)

   PMID 42542926Source