Carl read the papersWhat it actually is
TB-500 is a lab-made piece of Thymosin Beta-4 (TB4), a naturally-occurring protein found in nearly all cells. TB4 plays a role in building new blood vessels, cell migration and wound closure.
Where BPC-157 is often used near a specific injury, TB-500 is described as more systemic — spreading widely and acting body-wide, which is why the two are so often combined.
How it’s thought to work
- Actin regulation — binds actin, a protein central to cell movement and structure.
- Cell migration — helps repair cells travel to injury sites.
- Angiogenesis — supports new blood-vessel formation for blood flow.
- Anti-inflammatory — reported for full-length thymosin beta-4 in models. That effect is linked to a different piece of the protein, not the part TB-500 copies.
What the research says
Most data is pre-clinical and animal-based, and most of it used full-length thymosin beta-4, not the short TB-500 fragment. TB-500 itself is sold as a veterinary product and is best known from racehorse doping cases. Human trials exist only for full-length thymosin beta-4 (for example small IV safety studies and eye drops). For TB-500 itself the FDA says it found no human exposure data at all.
- Muscle, tendon and ligament recovery.
- Flexibility and reduced adhesions/scar tissue (reported).
- Wound healing and cardiovascular repair models.
Watch: TB-500 explained
Video by Jeffrey Peng MD on YouTube. Not affiliated with Peptide Carl and not an endorsement — included because a second explanation of the same mechanism is often what makes it click.
Reported protocols
These are the doses the peptide community actually reports running (Reddit & forums), alongside published research — logged for education, not as a recommendation to use.
| Parameter | Commonly reported range |
|---|---|
| Community dose | 2–2.5 mg (loading); 2 mg (maintenance) |
| Frequency | Loading 2×/week ×4 wks → then 1×/week |
| Route | SubQ (some IM near injury) |
| Cycle | ~4–6 wk loading, then weekly (6–8+ wks total) |
| Community tip | Long half-life = infrequent dosing; refrigerate, use within ~28 days; run with BPC-157 |
Common use cases
| Goal | Community protocol notes |
|---|---|
| Systemic recovery | 2–2.5 mg 2×/wk loading, then 1×/wk |
| Flexibility / scar tissue | weekly maintenance, 6–8+ wks |
| With BPC-157 (Wolverine) | 2 mg TB 2×/wk + 250–500 mcg BPC daily |
Mixing it (reconstitution)
Freeze-dried peptides must be reconstituted with bacteriostatic water before they can be measured. Carl’s calculator turns “mg in the vial + ml of water + target dose” into “units on the syringe” — and tells you how long the vial lasts.
→ Open the Reconstitution Calculator
Injection & handling
SubQ (some IM near an injury), 2–2.5 mg — loading twice weekly for ~4 weeks, then weekly. The weekly habit rests on a long half-life that has never been measured in people. Don’t blast BAC water onto the powder; refrigerate reconstituted, use within ~28 days.
Stacks it appears in
- The Wolverine — BPC-157 + TB-500 — sold as local plus body-wide repair. The one rat study of the pair (2026) found no extra benefit over either alone.
Sources
- TB-500 is Ac-LKKTETQ, horse doping control, J Chromatogr A 2012 (PMID 23084823)
- Active sites of thymosin beta-4, FASEB J 2010 (PMID 20179146)
- Actin-binding site promotes angiogenesis, FASEB J 2003 (PMID 14500546)
- Thymosin beta-4 and wound healing in rats, J Invest Dermatol 1999 (PMID 10469335)
- Thymosin beta-4 and cardiac repair, Nature 2004 (PMID 15565145)
- First-in-human IV recombinant thymosin beta-4, J Cell Mol Med 2021 (PMID 34346165)
- RGN-259 thymosin beta-4 eye drops, phase 3, Int J Mol Sci 2022 (PMID 36613994)
- BPC-157 plus TB-500 in rat Achilles repair, Jt Dis Relat Surg 2026 (PMID 42542926)
- FDA: bulk substances that may present significant safety risks (Apr 2026)
- WADA 2026 Prohibited List
