TB-500
Thymosin Beta-4 Fragment
TB-500 is a synthetic version of a 43-amino-acid segment of thymosin beta-4, a naturally occurring protein involved in cell migration, wound healing, and tissue repair. It is one of the most widely used healing peptides, frequently stacked with BPC-157 for injury recovery. TB-500 promotes angiogenesis, reduces inflammation, and supports cellular differentiation in damaged tissues.
Quick Reference
Dosing Protocols
TB-500 protocols typically start with a loading phase to saturate tissue levels, followed by a lower maintenance dose. Unlike BPC-157, TB-500 is injected less frequently due to its longer half-life.
Loading Phase
4-8 mg/week
Split into 2 injections (2-4 mg each)
2-4 weeks
Front-loads tissue levels. Higher end (8 mg/week) for acute injuries. Start with 4 mg/week for general healing.
Maintenance Phase
2-4 mg/week
1-2 injections per week
4-8 weeks
Sustains healing after initial loading. Some users drop to 2 mg/week once improvement is noticeable.
Injury Recovery (Aggressive)
5-10 mg/week
Split into 2-3 injections
2-3 weeks loading, then taper
For significant injuries (tears, post-surgical). Higher doses for shorter periods. Taper to maintenance after acute phase.
Preventive / Low-Dose
2 mg/week
1x/week
Ongoing or 8-12 week cycles
For athletes or active individuals seeking injury prevention and recovery support. Can run longer cycles at low doses.
Reconstitution Guide
TB-500 comes as a lyophilized powder and requires reconstitution with bacteriostatic water before injection.
Example: 5 mg vial + 1 mL BAC water
Concentration: 5,000 mcg ÷ 1 mL = 5,000 mcg/mL (5 mg/mL)
For a 2.5 mg dose: 2,500 ÷ 5,000 = 0.50 mL = 50 units on a 100-unit syringe
Doses per vial: 5 mg ÷ 2.5 mg = 2 doses at 2.5 mg
Example: 5 mg vial + 2 mL BAC water
Concentration: 5,000 mcg ÷ 2 mL = 2,500 mcg/mL (2.5 mg/mL)
For a 2.5 mg dose: 2,500 ÷ 2,500 = 1.00 mL = 100 units on a 100-unit syringe
For a 5 mg dose: Requires full vial (2.0 mL)
TB-500 reconstitution tips
- TB-500 dissolves easily — it typically reconstitutes faster than BPC-157
- Use less BAC water (1 mL) to keep injection volumes manageable since doses are larger (mg vs mcg)
- Gently swirl, do not shake. TB-500 is stable but shaking can introduce bubbles
- Store reconstituted vials in the refrigerator. Use within 3-4 weeks
Injection Sites
TB-500 can be injected subcutaneously or intramuscularly. Unlike BPC-157, TB-500 is considered more systemic — it does not need to be injected near the injury site.
- Abdomen (subcutaneous) — most common site. Pinch belly fat, inject at 45-degree angle
- Deltoid (intramuscular) — for users who prefer IM injection. 25-27 gauge needle recommended
- Glute (intramuscular) — alternative IM site for larger volumes
Rotate injection sites between doses. TB-500 is systemic, so injection location is less critical than with BPC-157.
Side Effects
TB-500 is generally well-tolerated. Most reported side effects are transient and mild:
Injection site irritation
Head rush / lightheadedness
Temporary lethargy
Nausea
Headache
Temporary increased heart rate
Note on cancer concern: Thymosin beta-4 is upregulated in some cancer cell lines, which has raised theoretical concerns. However, no causal link between TB-500 administration and cancer development has been established in research. Individuals with active malignancies should consult their oncologist before use.
Common Stacks
TB-500 + BPC-157
— Maximum healingThe gold standard healing stack. TB-500 provides systemic anti-inflammatory and cell-migration effects while BPC-157 promotes localized angiogenesis and growth factor expression. Together they cover complementary healing pathways.
Typical dosing: TB-500 2.5-5 mg 2x/week + BPC-157 250-500 mcg daily. Run for 4-6 weeks.
TB-500 + GHK-Cu
— Tissue remodeling + collagenCombines TB-500's wound healing with GHK-Cu's collagen synthesis stimulation. Effective for post-surgical recovery and chronic soft tissue injuries.
Typical dosing: TB-500 2.5-5 mg 2x/week + GHK-Cu 1-2 mg daily
TB-500 + BPC-157 + CJC-1295/Ipamorelin
— Full recovery protocolAdding a GH secretagogue stack amplifies healing through elevated growth hormone and IGF-1. Used for major injuries or comprehensive post-surgical recovery.
Typical dosing: TB-500 2.5 mg 2x/week + BPC-157 250-500 mcg/day + CJC/Ipa 100/100 mcg before bed
Research Summary
Thymosin beta-4 (the parent protein of TB-500) has been studied extensively. Key findings:
Thymosin beta-4 accelerated wound closure, increased angiogenesis, and promoted keratinocyte migration in dermal wound models
Malinda et al., 1999, J Invest Dermatol
Promoted cardiac cell migration and survival following myocardial infarction; reduced scar formation in mouse heart models
Bock-Marquette et al., 2004, Nature
Reduced expression of pro-inflammatory cytokines (NF-kB pathway) and promoted anti-inflammatory mediators in corneal injury models
Sosne et al., 2007, Expert Opin Biol Ther
FDA Orphan Drug designation for epidermolysis bullosa based on demonstrated acceleration of corneal wound healing
RegeneRx Biopharmaceuticals, FDA Orphan Drug Status
Stimulated hair follicle stem cell differentiation and promoted hair growth in animal models
Philp et al., 2004, FASEB J
Note: Most studies use thymosin beta-4 (full protein). TB-500 is a synthetic fragment. Results may not directly translate. No completed human clinical trials for TB-500 specifically.
FAQ
What is the difference between TB-500 and thymosin beta-4?
Thymosin beta-4 is the full 43-amino-acid protein found naturally in the body. TB-500 is a synthetic peptide fragment containing the active region of thymosin beta-4. TB-500 is what is commercially available; full thymosin beta-4 is used in clinical research.
Do I need to inject TB-500 near the injury?
No. Unlike BPC-157, TB-500 is considered fully systemic. It reaches injured tissue regardless of injection site. Most users inject subcutaneously in the abdomen for convenience.
How quickly does TB-500 work?
Most users notice improvement within 2-3 weeks, with significant progress by weeks 4-6. Acute injuries may respond faster. The loading phase accelerates initial tissue saturation.
Can I take TB-500 and BPC-157 in the same syringe?
Many users draw both peptides into the same syringe for a single injection. While there are no formal stability studies on combining them, this is common practice in the community without reported issues.
How should I store TB-500?
Unreconstituted: store at room temperature or refrigerated (refrigerated preferred). Reconstituted: refrigerate at 2-8°C. Use reconstituted TB-500 within 3-4 weeks.
Is TB-500 banned in sports?
Yes. TB-500 (thymosin beta-4) is prohibited by WADA and most athletic organizations under the category of peptide hormones, growth factors, and related substances.
Calculate your TB-500 dosing
Get exact syringe units for your vial size and BAC water volume.