TB-500 (Thymosin Beta-4 Fragment)
Synthetic Fragment (17-23) of Thymosin Beta-4
Community Research
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A synthetic 7-amino acid fragment corresponding to the actin-binding region of thymosin beta-4, originally developed for equine use with retained tissue repair properties. TB-500 acts as principal actin-sequestering protein, regulating cell migration, promoting angiogenesis, reducing inflammation, and activating stem cell differentiation.
Acts as principal actin-sequestering protein, regulating cell migration, promoting angiogenesis, reducing inflammation, and activating stem cell differentiation for comprehensive regenerative effects.
Molecular Data
Ac
Position 1
Serine
Position 2
Aspartic Acid
Position 3
Lysine
Position 4
Proline
Position 5
Position 6
Methionine
Position 7
Alanine
Position 8
Glutamic Acid
Position 9
Isoleucine
Position 10
Position 11
Position 12
Phenylalanine
Position 13
Position 14
Position 15
Position 16
Position 17
Leucine
Position 18
Position 19
Position 20
Threonine
Position 21
Position 22
Position 23
Glutamine
Position 24
Position 25
Position 26
Asparagine
Position 27
Position 28
Position 29
Position 30
Position 31
Position 32
Position 33
Position 34
Position 35
Position 36
Position 37
Position 38
Position 39
Position 40
Position 41
Glycine
Position 42
Position 43
Position 44
Research Indications
Accelerated healing of muscle fibers with reduced recovery time and enhanced repair via cell migration and differentiation.
Connective tissue repair with reduced scar formation and improved biomechanical properties of healing tissues.
Enhanced dermal closure, improved angiogenesis, and reduced inflammation in acute and chronic scenarios.
Faster recovery from intense training with reduced muscle soreness and improved tissue repair.
Strengthened tissues through enhanced repair mechanisms may reduce injury risk.
Improved muscle quality through enhanced regeneration and repair pathways.
Protective effects against neuronal damage in various models.
Preclinical evidence for improved outcomes in spinal injury models.
Potential neuroprotective and regenerative effects on brain tissue.
Dosing Protocols
Subcutaneous or intramuscular injection. Flexible timing with no empty stomach requirement. Can be injected near injury site for localized effect.
General tissue repair
2-3mg
2x weekly
SubQ or IM
Serious injury recovery
4-5mg
3x weekly
SubQ near injury site
Athletic enhancement
SubQ
Chronic conditions
3-4mg
2-3x weekly
Maintenance
2mg
1-2x weekly
Post-surgical recovery
3-5mg
Reconstitution Instructions
Bacteriostatic water (BAC)
Insulin syringes (1mL recommended)
Alcohol swabs
TB-500 vial (2mg or 5mg typical)
Sterile work surface
1 Clean work area and hands thoroughly with alcohol
2 Calculate required BAC water volume
3 Draw calculated BAC water slowly into syringe
4 Inject BAC water slowly down vial side (never directly on powder)
5 Gently swirl vial until powder completely dissolves
6 Store reconstituted solution refrigerated, use within 28 days
Interactions
What to Expect
Side Effects & Safety
Common Side Effects
Generally minimal side effects
Possible mild injection site reactions
Temporary fatigue in some users
Stop Signs - Discontinue if:
Persistent or worsening injection site infections
Unusual swelling or prolonged redness
Severe allergic reactions
Unexpected systemic symptoms
Concerning health changes
Contraindications
Active cancer treatment (due to angiogenic effects)
Pregnancy or breastfeeding
Immunosuppressive medications (consult provider)
WADA prohibited for competitive athletes
Quality Checklist
Good Signs
White lyophilized powder - fine, evenly distributed with light fluffy texture
Clear, colorless solution after reconstitution with no particles
Proper vacuum seal intact with secure rubber stopper
Warning Signs
Slight powder clumping acceptable if completely dissolves with gentle swirling
Bad Signs
Colored or crystalline powder (yellow/brown indicates degradation)
Persistent cloudiness, floating particles, or precipitation
Damaged vial seal or contamination signs
Frequently Asked Questions
Can TB-500 be injected directly at the injury site or must it be systemic?
TB-500 can be injected directly near injury sites or systemically. Local injection near tendon/ligament injuries may accelerate healing by concentrating effects, but systemic SubQ or IM administration provides comprehensive tissue repair through systemic circulation and is more commonly used.
How long do TB-500 benefits persist after stopping the protocol?
TB-500's healing benefits persist for weeks to months after completing a 6-8 week cycle due to sustained improvements in tissue quality, angiogenesis, and stem cell mobilization. However, maintenance doses every 1-2 weeks may be needed for chronic conditions requiring ongoing support.
Is TB-500 banned in sports and why?
Yes, TB-500 is prohibited by WADA in competitive sports because it enhances cellular regeneration and muscle repair, providing unfair athletic advantage. Athletes should avoid use if subject to anti-doping testing.
What's the difference between TB-500 and the TB-500 fragment (Ac-LKKTETQ)?
Full TB-500 is the complete 43-amino-acid thymosin beta-4, while the fragment is just the bioactive 7-amino-acid core (LKKTETQ). Both work similarly, but the fragment is smaller, more stable, and potentially more economical while retaining core wound-healing and regenerative properties.
References
In two Phase 2 clinical trials, thymosin beta-4 accelerated healing of chronic pressure ulcers and venous stasis ulcers by almost a month compared to placebo, with confirmed safety and tolerability.
Synthetic thymosin beta-4 given intravenously was well tolerated with no dose-limiting toxicity; promotes cardiomyocyte migration and survival, and stimulates coronary vasculogenesis for cardiac ischemia treatment.
Chronic thymosin beta-4 administration increased the number of regenerating skeletal muscle fibers in exercised dystrophin-deficient (mdx) mice, showing potential for Duchenne muscular dystrophy treatment.
Phase 2 randomized trial in 9 severe dry eye patients showed RGN-259 (0.1% thymosin beta-4) eye drops achieved statistically significant improvements in both signs and symptoms, with effects lasting 28 days post-treatment.
Phase I study in 54 healthy subjects with ascending doses (0.05-25.0 mcg/kg) demonstrated mild to moderate adverse events with no dose-limiting toxicities or serious adverse events.
Phase III trial demonstrated thymosin beta-4 ophthalmic solution promotes corneal healing and improves comfort in neurotrophic keratopathy, advancing toward FDA approval.
Related Peptides
Complementary healing mechanisms with enhanced tissue repair when combined (Wolverine Stack).
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No negative interactions; potential enhanced recovery.
Different receptor families with no pathway overlap.
Disclaimer
This information is for educational and research purposes only. Consult a healthcare professional before use.