CalcMyPeptide
Healing & RecoveryAlso known as: Thymosin Beta-4, Tβ4

TB-500

TB-500 is a synthetic fraction of the naturally occurring mammalian protein Thymosin Beta-4 (Tβ4). It is a highly systemic, non-localized regenerative agent favored in clinical recovery protocols for its unparalleled ability to suppress chronic inflammation and facilitate soft tissue regeneration. Due to its extremely low molecular weight, TB-500 moves seamlessly through the bloodstream to target areas of acute trauma, making it a staple in advanced longevity clinics and elite athletics for healing muscle tears and ligament damage.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Moderate4 peer-reviewed citations

Quick Stats

Half-LifeVariable (12-24 hours)
Dose Range2-5 mg twice weekly
Frequency2× weekly (loading), 1× weekly (maintenance)
Vial Sizes5 mg, 10 mg
BioavailabilityNear 100% (subcutaneous)
Year DevelopedSynthesized 1980s

Scientific Data

Molecular Formula
C38H68N10O14
Molecular Weight
889.02 g/mol
CAS Number
PubChem ID
Developer
Not applicable (endogenous protein fragment)

Mechanism of Action

TB-500 is a synthetic version of Thymosin Beta-4 (Tβ4), a 43-amino-acid protein naturally produced by the thymus gland. Its primary mechanism involves regulation of actin, a cell-building protein critical for cell migration, wound healing, and tissue repair. TB-500 promotes actin polymerization, enabling cells to migrate to injury sites more efficiently.

TB-500 also stimulates angiogenesis (new blood vessel formation), reduces inflammation, and promotes the formation of new muscle fibers. It has been studied extensively in equine medicine for tendon and ligament repair. Its systemic distribution means it does not need to be injected at the injury site — it locates and repairs damaged tissue throughout the body.

Source: PMID: 20435714

Background & History

Thymosin Beta-4 (Tβ4) was first identified in 1966 by Allan Goldstein at the National Cancer Institute as a thymic hormone involved in immune regulation. TB-500 is the synthetic form of the active region of Tβ4 (amino acids 17–23). It became widely studied in equine sports medicine in the 2000s after showing dramatic efficacy for tendon and muscle repair in racehorses, which led to its ban by racing authorities and subsequent interest in human applications.

Research Use Cases

  • Systemic tissue repair without site-specific injection
  • Cardiac muscle repair and protection post-ischemia
  • Reducing inflammation in chronic musculoskeletal conditions
  • Hair follicle regeneration and wound healing
  • Post-surgical recovery acceleration

Dosing Protocol

Typical Dose2-5 mg twice weekly
Frequency2× weekly (loading), 1× weekly (maintenance)
Half-Life~2 hours (active metabolites longer)
Common Vial Sizes5 mg, 10 mg

Dosing Protocols

Loading Phase (Weeks 1-6)

Dose
2 - 5 mg
Frequency
twice weekly
Note: Systemic distribution — does not need to be injected at the injury site.

Maintenance

Dose
2 mg
Frequency
once weekly
Note: Alternatively 1 mg twice weekly to maintain elevated tissue actin regulation.

Body-Weight Dosing Reference

Estimated doses extrapolated from the published research range of 20005000 mcg/day (referenced to 70 kg / 154 lb). These are approximations — consult a qualified healthcare provider for personalised guidance.

WeightLowTargetHigh
120 lb(54 kg)1543 mcg2700 mcg3857 mcg
140 lb(63 kg)1800 mcg3150 mcg4500 mcg
160 lb(73 kg)2086 mcg3650 mcg5214 mcg
180 lb(82 kg)2343 mcg4100 mcg5857 mcg
200 lb(91 kg)2600 mcg4550 mcg6500 mcg
220 lb(100 kg)2857 mcg5000 mcg7143 mcg
250 lb(113 kg)3229 mcg5650 mcg8071 mcg

💉 For exact syringe units based on your vial concentration, use the TB-500 Reconstitution Calculator →

Administration

Route
Subcutaneous injection
Timing
Any time of day. Does not require site-specific injection due to systemic action.
Fasting Required?
No — food timing not critical

Expected Timeline

1-2 weeks
Initial reduction in acute pain and swelling at injury sites.
3-4 weeks
Noticeable improvement in joint/tendon mobility and structural recovery.
6+ weeks
Maximal tissue repair benefits; user typically shifts to maintenance dosing.

Who Is It For?

Muscle/Tendon Healing

High

Extensively studied in veterinary medicine for accelerating repair of injured tissues.

Anti-Inflammatory

Moderate

Observed to reduce local and systemic inflammatory markers in experimental models.

Reconstitution Example

Vial
5 mg
Water
2 mL
Concentration
2.5 mg/mL
Per Unit (100u syringe)
25 mcg
Dose of 2000 mcg = 80 units on a 100-unit insulin syringe

Safety & Considerations

TB-500 is a research peptide. It is not FDA-approved for human use. Animal studies show a favorable safety profile. Due to its angiogenic properties, TB-500 should not be used by individuals with active cancer. Use sterile injection practices.

Regulatory & Legal Status

FDA Status (US)
Research Only
WADA Status (2026)
Prohibited (S0)

Competitive athletes subject to anti-doping controls should not use TB-500.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Contraindicated with active malignancy due to angiogenic activity. May increase healing response in tissues with existing inflammation — start at lower end of dose range. No significant interactions with common medications documented in research.

Synergies & Common Stacks

Classic recovery stack: TB-500 provides systemic, body-wide healing via actin regulation; BPC-157 handles localized vascular and GI repair. Complementary mechanisms with additive effect.

IGF-1 LR3 promotes cellular proliferation while TB-500 facilitates migration of those cells to injury sites, enhancing overall regenerative capacity.

TB-500 vs. BPC-157

AttributeTB-500BPC-157
MechanismActin polymerization (systemic)VEGF/FGF angiogenesis (localized)
InjectionAny site — distributes systemicallyNear injury site preferred
Dose2–5 mg 2× weekly250–500 mcg 1–2× daily
Best ForWhole-body healing signalsLocalized injury + GI healing
WADA StatusProhibited (S0)Prohibited (S0)

Verdict: Stack both for maximum synergy: TB-500 handles systemic healing signals and cell migration while BPC-157 drives local angiogenesis and GI mucosal protection.

Dosing Quick Reference

TB-500— Dosing Guide
Dose Range
2-5 mg twice weekly
Half-Life
~2 hours (active metabolites longer)
Frequency
2× weekly (loading), 1× weekly (maintenance)
Route
Subcutaneous
5 mg vial10 mg vial
💧 2 mL BAC water📐 2.5 mg/mL concentration💉 25 mcg/unit (100u syringe)
Healing & Recoverycalcmypeptide.com

Frequently Asked Questions

What is the typical TB-500 dosing protocol?
Loading phase: 2-5 mg twice weekly for 4-6 weeks. Maintenance: 2 mg once weekly. TB-500 distributes systemically and does not require site-specific injection.
How long does TB-500 take to work?
Most users report initial improvements within 1-2 weeks of the loading phase. Full benefits typically manifest after 4-6 weeks of consistent dosing.
What is the difference between TB-500 and Thymosin Beta-4?
TB-500 is a synthetic fragment of the full Thymosin Beta-4 protein. While they share the same active region, TB-500 is more cost-effective and commonly available for research use.

References

  1. Crockford et al. "Thymosin beta-4 and its synthetic fragment TB-500 in tissue repair".” Annals of the New York Academy of Sciences (2010). PMID: 20388147

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