TB-500 vs Thymosin Alpha-1
Overview
TB-500 is primarily a bone & joint peptide, while Thymosin Alpha-1 is used for immune support.
This page compares TB-500 and Thymosin Alpha-1 across their primary use, typical dosing, reported benefits and side effects, and U.S. regulatory status. For the full monograph on either compound — mechanism of action, clinical research, and references — follow the article links.
Side-by-side comparison
| TB-500 | Thymosin Alpha-1 | |
|---|---|---|
| Category | Bone & Joint | Immune Support |
| Regulatory status (US) | Compounding (Rx) — Apr 2026 | Research use only |
| Typical dosage | 2-5 mg | 1.6-3.2 mg |
| Frequency | weekly | twice weekly |
| Reported benefits | Bone healing, joint mobility, connective tissue support | Enhanced immune function, antiviral properties, vaccine response improvement, cancer therapy support |
| Reported side effects | Well-tolerated | Well-tolerated, rare injection site reactions |
Key differences
Primary use. TB-500 is categorised under Bone & Joint, while Thymosin Alpha-1 falls under Immune Support. Their differing categories mean they are usually chosen for different goals rather than as direct substitutes.
Regulatory status. TB-500: not FDA-approved; compounding permitted with a prescription as of April 2026. Thymosin Alpha-1: not FDA-approved; treated as a research compound.
Dosing. TB-500 is typically dosed at 2-5 mg (weekly). Thymosin Alpha-1 is typically dosed at 1.6-3.2 mg (twice weekly).
Can you stack them?
Some protocols combine peptides, but stacking TB-500 and Thymosin Alpha-1 has not been validated for safety or efficacy in controlled trials. Combining compounds can change their effects and risks. Nothing here is medical advice — consult a qualified healthcare provider before starting or combining any protocol.
Frequently asked questions
- What is the difference between TB-500 and Thymosin Alpha-1?
- TB-500 is primarily a bone & joint peptide, while Thymosin Alpha-1 is used for immune support. TB-500 is not FDA-approved; compounding permitted with a prescription (as of April 2026), whereas Thymosin Alpha-1 is not FDA-approved; generally classified as a research compound.
- What is TB-500 used for?
- Connective tissue repair.
- What is Thymosin Alpha-1 used for?
- Potent immune modulator.
- Can you take TB-500 and Thymosin Alpha-1 together?
- Some users combine peptides within a single protocol, but stacking TB-500 and Thymosin Alpha-1 has not been established as safe or effective in controlled trials. Neither this comparison nor PeptideSciences101 is medical advice — consult a qualified healthcare provider before combining any compounds.
- Is TB-500 or Thymosin Alpha-1 FDA-approved?
- TB-500 is not FDA-approved; compounding permitted with a prescription (as of April 2026). Thymosin Alpha-1 is not FDA-approved; generally classified as a research compound.
Read the full articles
- TB-500 — full monograph: mechanism, research, dosing & references
- Thymosin Alpha-1 — full monograph: mechanism, research, dosing & references