TB-500
WELL RESEARCHEDAc-LKKTETQ | Synthetic fragment (17-23) of thymosin beta-4
Updated: August 2026 · Based on the available preclinical literature.
Key points
- What it is: synthetic fragment of thymosin beta-4, a tissue-regeneration protein.
- Main use: systemic tissue healing, injury recovery and flexibility.
- Typical dose: 2–2.5 mg twice a week (loading), then once a week (maintenance).
- Timeline: skin healing in 3–7 days; more severe injuries 4+ weeks.
- Common effects: mild; redness at the injection site, temporary fatigue.
- Comparison: systemic (whole-body) action; combined with BPC-157 (localized).
- Status: not FDA-approved and banned by WADA.
Overview
What is TB-500?
TB-500 is a synthetic 7-amino-acid fragment (Ac-LKKTETQ) corresponding to the active actin-binding region (positions 17-23) of thymosin beta-4. Originally developed for veterinary use in horses, this fragment retains tissue-repair and anti-inflammatory properties while being more stable than the full peptide. It is banned by WADA for its performance-enhancing effects.
Key benefits
Superior systemic tissue repair, accelerated healing of muscles, tendons, ligaments and organs. Enhanced cell migration and angiogenesis for comprehensive regenerative effects.
Mechanism of action
Injectable TB-500 distributes systemically to repair tissues throughout the body. It acts as the main actin-sequestering protein, regulating cell migration, promoting angiogenesis, reducing inflammation and activating stem cell differentiation for accelerated healing.
Quick start guide
Dosing protocol
| Phase | Dose | Frequency | Duration |
|---|---|---|---|
| Loading | 2–2.5 mg | 2 times/week | 4–6 weeks |
| Maintenance | 2–2.5 mg | 1 time/week | Continue as needed |
Subcutaneous route. The specific dose must be assessed by a healthcare professional.
🧮 Calculate your exact syringe dose →BPC-157 vs TB-500
| BPC-157 | TB-500 | |
|---|---|---|
| Origin | Gastric juice | Thymosin beta-4 |
| Action | Localized | Systemic |
| Best for | Specific injury, gut | Multiple or diffuse injuries |
| Half-life | Short | Long |
| Stackable | Yes (with TB-500) | Yes (with BPC-157) |
⚠️ Who should NOT use it
- Caution due to the effect on angiogenesis (theoretical consideration in cancer) — consult first.
- Pregnancy or breastfeeding.
- Competitive athletes (banned by WADA).
- Always under the supervision of a healthcare professional.
What to expect
- Week 1-2: reduced inflammation and better tissue sensation.
- Week 2-4: accelerated healing rate and better tissue quality.
- Week 4-8: maximum tissue repair and regenerative benefits.
- Week 6-12: continued improvement in tissue strength and function.
- Side effects: generally minimal, possible injection-site reactions.
- Most effective for: muscle, tendon, ligament and soft-tissue injuries.
Side effects & safety
- Use a sterile injection technique to prevent infection.
- Mild injection-site reactions are normal and temporary.
- Consult your healthcare provider if you take immunosuppressive medication.
- Not recommended during active cancer treatment.
- Avoid during pregnancy or breastfeeding.
- Banned by WADA — not for competitive athletes.
- Allergic reaction: rash, itching or swelling.
- Signs of infection at the injection site: redness, warmth, pus or intense pain.
- Any abnormal growth or lump (due to its effects on angiogenesis).
- Chest pain, difficulty breathing or irregular heartbeat.
- Extreme fatigue or persistent malaise.
- If you are pregnant, breastfeeding or planning a pregnancy.
Frequently asked questions
What is TB-500?
TB-500 is a synthetic 7-amino-acid fragment (Ac-LKKTETQ) corresponding to the active actin-binding region of thymosin beta-4.
What is TB-500 researched for?
It is studied for systemic tissue repair, muscle and tendon recovery, and inflammation reduction.
How does TB-500 work?
It acts as an actin-sequestering protein, promoting cell migration, angiogenesis and tissue regeneration throughout the body.
How long does TB-500 take to work?
In the literature, effects on inflammation are described within 1-2 weeks and tissue-repair effects around 2-4 weeks.
What is the usual TB-500 dose?
Published protocols use 2-5 mg per week, split into 2-3 applications. The schedule should be assessed by a professional.
How is TB-500 administered?
Subcutaneously or intramuscularly; being systemic, it does not need to be injected at the injury site.
How is TB-500 stored?
As a powder, refrigerated; reconstituted, in the fridge (2-6 °C), using it within a few weeks. More details in the storage guide.
What are the possible side effects of TB-500?
It is usually described as well tolerated, with possible mild reactions at the injection site. Long-term safety data in humans are lacking.
Which peptides is TB-500 combined with?
The most cited combination is TB-500 with BPC-157 for tissue and injury recovery.
What is the difference between TB-500 and BPC-157?
TB-500 has a more systemic action (whole body), while BPC-157 is associated with a more localized action.
Is TB-500 approved?
It is not approved for human use and is banned by WADA in competitive sport.
Research areas
- Systemic tissue repair
- Muscle and tendon recovery
- Cell migration and angiogenesis
- Inflammation reduction
- Flexibility and mobility
Related peptides
- BPC-157 — Pentadecapeptide researched for localized tissue repair.
- CJC-1295 — GHRH analog, related to growth hormone.
- Ipamorelin — Selective GHRP, associated with recovery and body composition.
Related articles
Related topics
- TB-500 for muscles
- TB-500 for tendons
- TB-500 and recovery
- TB-500 vs BPC-157
- TB-500 and mobility
- TB-500 and connective tissue
Summary
What it is: Synthetic 7-amino-acid fragment of thymosin beta-4.
How it is researched: Subcutaneous or intramuscular, 2-5 mg per week in 2-3 applications.
Key features: Systemic action; associated with cell migration and angiogenesis. Not approved for human use and banned by WADA.
Related peptides: BPC-157, CJC-1295 and Ipamorelin.