
Thymosin Beta-4 (TB-4) is a naturally occurring 43-amino-acid peptide involved in tissue repair, angiogenesis, and cell migration. It's the most abundant actin-sequestering molecule in mammalian cells and the parent molecule of the TB-500 fragment.
Research-context information only. Thymosin beta-4 is a research peptide. Protocols, doses, and reactions reported below come from published research and self-reported community sources. This article reports what has been documented, not what should be done. Consult a licensed physician for personal medical decisions.
No FDA-approved human dosing exists. Everything below is extrapolated from animal research and community experience. This is not medical advice.
Thymosin Beta-4 Dosing Table
Match your vial size below — reconstitution and dose math update automatically.
| Dose | Syringe units | mL volume | Schedule |
|---|---|---|---|
| 750 mcg | 15 units | 0.15 mL | 2x/week SubQMaintenance |
| 1.5 mg | 30 units | 0.3 mL | 2x/week SubQLoading (weeks 1-4) |
| 2.5 mg | 50 units | 0.5 mL | Weekly SubQ |
Math assumes U-100 insulin syringes (1 mL = 100 units). Verify your syringe matches before injecting. Round half-units to the nearest visible mark.
Quick Reference: Community Protocol
| Parameter | Community Protocol |
|---|---|
| Loading dose | 500 mcg - 1 mg daily (weeks 1-2) |
| Maintenance dose | 500 mcg 2x/week (weeks 3-8) |
| Route | Subcutaneous injection (near injury or abdomen) |
| Timing | AM |
| Cycle | 4-8 weeks total |
| Vial size | 10 mg |
| Reconstitution | 2 mL bacteriostatic water → 5 mg/mL |
| Syringe reading (750 mcg) | 15 units on insulin syringe |
| Storage | Refrigerate, use within 28 days |
Loading phase: 500 mcg to 1 mg daily for 2 weeks to achieve tissue saturation. Maintenance: 500 mcg twice weekly for 2-6 additional weeks. For the full TB-4 profile, vendor pricing, and comparison with TB-500, see our Thymosin Beta-4 peptide page.
Cycling Details
TB-4 uses a two-phase approach: loading then maintenance. The loading phase (2 weeks daily) saturates tissue levels during the acute healing window. TB-4's short plasma half-life (~2 hours) means frequent dosing is needed for consistent tissue-level concentrations.
The maintenance phase (2x weekly) sustains support while reducing peptide consumption. This mirrors tissue repair timelines seen in animal studies — rapid cell migration and angiogenesis in weeks 1-2, followed by ECM remodeling in weeks 3-8 (Malinda et al., 1999).
Typical protocol lengths: Tendon/ligament/muscle injuries: 4-6 weeks. Skin and wound healing: 4-8 weeks. Post-surgical recovery: 6-8 weeks. Chronic inflammatory conditions: 8-12 weeks with cycling.
Routes of Administration
Subcutaneous (most common): For localized injuries, community protocols describe injecting within a few inches of the injury site. For systemic healing, the abdomen or anywhere with subcutaneous fat is used. A 29-31 gauge insulin syringe is commonly cited.
Intramuscular: Used when targeting a specific muscle injury — direct injection into the muscle belly. Less common than subcutaneous.
Peri-lesional: Direct injection around wound sites, used in dermal wound research.

Reconstitution Quick Reference
| Vial Size | BAC Water | Concentration | 750 mcg Dose | 1 mg Dose |
|---|---|---|---|---|
| 10 mg | 2 mL | 5 mg/mL | 15 units | 20 units |
10 mg vial + 2 mL BAC water = 5 mg/mL. At this concentration, 750 mcg corresponds to 15 units on a standard insulin syringe; 1 mg is 20 units.
Community reconstitution protocols describe swirling gently rather than shaking, refrigerating at 2-8°C, and discarding after 28 days.




