The TL;DR.
TB-500 is the synthetic equivalent of Thymosin Beta-4 (Tβ4), a peptide that regulates actin. By upregulating actin, TB-500 promotes the migration of cells to the site of an injury, reduces inflammation, and accelerates the healing of muscle, tendon, and skin tissue well-established in animal models.[1]
While BPC-157 is often used for localized tendon/ligament repair, TB-500 is favored for larger muscle-belly tears and systemic, full-body recovery due to its longer half-life and systemic distribution. Like BPC-157, however, it lacks significant human clinical data and holds no FDA approval.[2]
How it's actually used.
Before you start
- Identify the goal. TB-500 is best suited for muscle tears and systemic inflammation.
- Understand the regulatory status. TB-500 cannot be legally prescribed or compounded in the US.
- Check your sport's rules. TB-500 is prohibited by WADA and most major sporting organizations.
Standard community dosing
Because of its longer half-life, TB-500 is typically dosed twice weekly rather than daily. community
Reconstitution math (injectable)
TB-500 typically arrives as a lyophilized powder in a 5 mg or 10 mg vial. It must be reconstituted with bacteriostatic water.
For a 5 mg vial · target 2.5 mg dose
- Add 2 mL of bacteriostatic water to the vial.
- Final concentration: 2.5 mg/mL.
- For a 2.5 mg dose: pull to the "100" mark on a 1 mL (100-unit) insulin syringe ≈ 1.0 mL (the entire syringe).
Injection site selection
- Community consensus: subcutaneous injection into abdominal fat is the standard approach. Because TB-500 acts systemically, local injection near the injury site is not considered necessary. community
Missed doses
- Missed 1 day: take the normal dose the next day.
- Missed 3+ days: resume the normal twice-weekly protocol.
Community consensus and real-world experience
In community discussions, TB-500 is highly regarded for its ability to heal large muscle tears (pectoral, hamstring) and reduce systemic joint inflammation. Users often report increased flexibility and reduced stiffness. community[9] It is almost universally stacked with BPC-157 for severe injuries. community[10]
Log every TB-500 injection on your recovery timeline.
Twice-weekly dosing for 6–8 weeks is hard to remember without a schedule. Epti tracks each injection alongside training load and pain ratings.
What to eat alongside.
Macronutrient adjustments
- Protein — 1.6–2.2 g/kg of body weight per day to support tissue regeneration.
Micronutrient adjustments
- Vitamin C — 500–1,000 mg daily. Essential for collagen synthesis, which TB-500 upregulates during the healing process.
Synergistic supplements
- Collagen peptides — 15–20 g daily, taken 60 min before rehab exercises.
Protective supplements
No data available — TB-500 has no known organ toxicity requiring specific protective supplements based on current animal models.
What can go wrong.
Reported side effects
Drug interactions
No formally documented drug interactions.
Contraindications
- Active cancer or history of cancer — TB-500 promotes cell migration and angiogenesis, which could theoretically accelerate tumor metastasis
- Autoimmune conditions (due to immunomodulatory effects)
Red flags
- Rapid, unexplained swelling or heat at the injection site (signs of infection)
- Severe allergic reaction — hives, difficulty breathing
Pregnancy, lactation & fertility
No data available — TB-500 has not been studied in pregnant or lactating women, nor has its effect on human fertility been evaluated. It should be strictly avoided in these populations.
Theoretical risks
- Cancer metastasis. Because Thymosin Beta-4 is highly expressed in metastatic cancer cells (aiding their migration), there is a theoretical risk that exogenous TB-500 could promote the spread of existing, undiagnosed cancers. emerging[3]
What to combine it with.
TB-500 + BPC-157 "Wolverine"
The most popular healing stack in the peptide community. BPC-157 promotes angiogenesis; TB-500 regulates actin and cell migration. They work through complementary pathways. community[10]
TB-500 + GHK-Cu
GHK-Cu stimulates collagen production; TB-500 reduces systemic inflammation and promotes cell migration. community
TB-500 + Ipamorelin / CJC-1295
Combines the actin-regulating properties of TB-500 with the GH-elevating properties of the secretagogues for maximum recovery support. community
Anti-pattern stacks — avoid
- TB-500 + active cancer. Theoretical risk of accelerating tumor metastasis via actin regulation and cell migration pathways.
How to train on it.
TB-500 is not a fat-loss or muscle-building peptide. Its sole role is recovery and healing.
Expected trajectory
Training adjustments
- Do not mask pain. Like BPC-157, TB-500 can reduce pain. Returning to heavy lifting too quickly can result in a re-tear.
Cut / recomp / bulk contexts
No data available — TB-500 does not directly influence caloric partitioning, fat oxidation, or muscle hypertrophy, making it neutral across all dietary phases.
How to store it.
Long-term freezer storage, up to 24 months.
Refrigerate. Beyond-use date: 28 days. Do not freeze reconstituted solution.
Light & freeze sensitivity
- Light — keep vials away from direct sunlight.
- Freeze — do not freeze the reconstituted solution.
Sourcing & legal access
- United States. Investigational new drug. Not approved for human use. Cannot be legally compounded.
- Cost-per-cycle (USD). Typically $100–$200 per month via research-chemical vendors (more expensive than BPC-157).
- Global. Not approved as a human therapeutic in any major jurisdiction.
What to track.
Because TB-500 is typically used for short cycles (4–8 weeks) and has no known organ toxicity, no specific blood markers are required for monitoring.
Baseline panel
Mid-cycle panel
No data available — mid-cycle testing is not standard practice for TB-500.
Post-cycle panel
Doctor handoff
vs. similar compounds.
| TB-500 | BPC-157 | GHK-Cu | KPV | |
|---|---|---|---|---|
| Primary mechanism | Actin regulation, cell migration | Angiogenesis, receptor upregulation | Collagen synthesis | Anti-inflammatory, mast-cell stabilization |
| Best for | Muscle tears, systemic inflammation | Tendons, ligaments, gut lining | Skin repair, cosmetic recovery | IBD, psoriasis, allergic responses |
| Route | SC | SC (injuries) / oral (gut) | SC or topical | SC, oral, or topical |
| Half-life | Long (days) | Short (minutes/hours) | Short | Short |
When to pick TB-500
Choose TB-500 for large muscle-belly tears or systemic, full-body inflammation.
When to pick BPC-157
Choose BPC-157 for localized, avascular tissue injuries (Achilles tendon, rotator cuff) or for gastrointestinal healing.
When to pick GHK-Cu
Choose GHK-Cu for skin repair and cosmetic recovery.
When to pick KPV
Choose KPV specifically for autoimmune-driven inflammation or mast-cell activation.
What the mechanism looks like.
Mechanism of action
TB-500 is a synthetic version of Thymosin Beta-4, a 43-amino acid peptide. Its primary mechanism of action is actin sequestration. It binds to G-actin monomers, preventing them from polymerizing into F-actin, which regulates the cellular cytoskeleton.[1]
By controlling actin dynamics, TB-500 promotes cell migration (particularly endothelial cells and keratinocytes) to the site of injury. It also reduces inflammation and promotes angiogenesis.[4]
Pharmacokinetics
No formal human pharmacokinetic studies have been published for TB-500 specifically. unknown In animal models, it has a longer half-life than BPC-157, which supports the twice-weekly dosing protocol used in the community.
Active metabolites
No data available — specific metabolic breakdown pathways in humans are not fully characterized.
Human clinical trials
Human clinical data for TB-500 is extremely limited.
| Study | n | Duration | Population | Result |
|---|---|---|---|---|
| Ruff et al. (2010) | Small | Single + multi-dose | Healthy volunteers | Well tolerated. No serious adverse events. Phase 1. |
Key animal studies
| Study | Model | Endpoint | Result |
|---|---|---|---|
| Philp et al. (2003) | Mice | Wound healing | Accelerated dermal healing and angiogenesis |
| Smart et al. (2007) | Mice | Cardiac repair | Promoted cardiomyocyte survival post-infarction |
| Sosne et al. (2002) | Rats | Corneal healing | Accelerated corneal re-epithelialization |
Open questions
- Does the theoretical risk of cancer metastasis hold true at therapeutic doses in humans?
- What is the actual subcutaneous bioavailability and half-life in humans?
Frequently asked.
TB-500 vs BPC-157: which is better?
They serve different purposes. BPC-157 is better for localized tendon/ligament injuries and gut health. TB-500 is better for large muscle tears and systemic inflammation. They are often stacked together.
How much TB-500 should I take?
The standard community protocol is 2.5 mg to 5 mg per week, typically divided into two subcutaneous injections (e.g., Monday and Thursday).
Does TB-500 build muscle?
No. It does not have direct anabolic properties. It aids in the repair of damaged muscle tissue but will not cause hypertrophy on its own.
Is TB-500 safe?
It has been well-tolerated in animal models and a small Phase 1 human trial, but long-term human safety data is completely lacking.
Does TB-500 cause cancer?
There is no evidence that it causes cancer. However, because it promotes cell migration and angiogenesis, there is a theoretical risk that it could accelerate the spread (metastasis) of existing cancers.
Does TB-500 need to be refrigerated?
Yes — once reconstituted with bacteriostatic water, it must be kept in the refrigerator and used within 28 days.
How long does it take TB-500 to work?
Users often report initial reductions in systemic inflammation within 1–2 weeks. Structural healing of muscle tears requires the full 4–8 week cycle.
Where it stands, by jurisdiction.
Last verified · May 17, 2026
Is TB-500 for you?
What we cited.
- Goldstein A.L., Hannappel E., Kleinman H.K. (2005). Thymosin beta-4: actin-sequestering protein moonlights to repair injured tissues. Trends Mol Med. 11(9):421–429. PMID: 16043407.
- Ruff D., Crockford D., Girardi G., Zhang Y. (2010). A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta-4 in healthy volunteers. Ann NY Acad Sci. 1194:223–229. PMID: 20536470.
- Cha H.J., Jeong M.J., Kleinman H.K. (2003). Role of thymosin beta-4 in tumor metastasis and angiogenesis. J Natl Cancer Inst. 95(22):1674–1680. PMID: 14625258.
- Philp D. et al. (2003). Thymosin beta 4 induces angiogenesis in vivo and in vitro. FASEB J. 17(14):2112–2114.
- Smart N. et al. (2007). Thymosin beta-4 induces adult epicardial progenitor mobilization and neovascularization. Nature. 445(7124):177–182.
- Sosne G. et al. (2002). Thymosin beta-4 promotes corneal wound healing and decreases inflammation in vivo following alkali injury. Exp Eye Res. 74(2):293–299.
- Reddit r/Biohackers. "My experience with TB500/BPC157." Accessed May 17, 2026.
- Reddit r/PlantarFasciitis. "BPC-157 and TB-500 therapy log." Accessed May 17, 2026.