Thymosin Alpha-1
A thymic peptide that modulates dendritic cell and T-cell function for balanced immune enhancement.
Medically reviewed by Dr. Jonathan Snipes, MD. Last reviewed May 6, 2026.What It Is
Thymosin Alpha-1 is a peptide naturally produced by the thymus gland. It's been approved in over 35 countries for immune modulation and has extensive clinical data.
How It Works
It enhances the function of dendritic cells and T-cells, helping your immune system better identify and respond to threats while maintaining balanced immune regulation.
Who It's For
Those looking to optimize immune function, recovering from chronic infections, or seeking immune support during recovery protocols.
Who Should Avoid It
Flag if on immunosuppressants. Not for organ transplant recipients without careful monitoring.
Protocol & Pricing
OBP Pharmacy Price
$80/15mg
You pay pharmacy price. No markup.
Starting Dose
20 units (0.6mg)
Form
Injectable vial (5mL, 3mg/mL, 15mg total)
Dosing Protocol
20 units subcutaneous injection daily. Maintenance dosing: 2–3 times per week. Acute viral illness: daily for 7–14 days, then taper to maintenance. 20 units = 0.2mL × 3mg/mL = 0.6mg per injection.
Beyond Use Date
90 Days from compounding (USP <797>)
Use within this window from the date your vial is compounded. BUD is set per USP <797> sterile compounding standards and printed on every label.
Stacking Guide
Stacks Well With
Related Peptides
Independently tested
Thymosin Alpha-1 lab test reports
Every Thymosin Alpha-1 batch dispensed by Optimal Balance Pharmacy is independently tested by Eagle Analytical Services (FDA-registered, A2LA ISO 17025 accredited) for sterility (ScanRDI) and bacterial endotoxin (USP <85>). The 2 most recent reports:
| Submission | Lot | Sample | Sterility | Endotoxin | |
|---|---|---|---|---|---|
| ETX-260325-0593 | 032526-13 | Thymosin Alpha-1 3mg/ml (5ml) | Pass | Pass <2 EU/mL / 375 EU/mL | Download |
| ETX-260325-0594 | 032526-23 | Thymosin Alpha-1 3mg/ml (5ml) | Pass | Pass <2 EU/mL / 375 EU/mL | Download |
Eagle Analytical Services is an independent FDA-registered laboratory, A2LA accredited to ISO 17025, based in Houston, Texas. They have no commercial relationship with PeptideRx. PeptideRx prescribes; Optimal Balance Pharmacy compounds and dispenses; Eagle tests every batch. Three separate companies. Browse our full quality program on the quality page.
Common questions about Thymosin Alpha-1
- What is thymosin alpha-1?
- Thymosin alpha-1 is a 28-amino acid peptide originally isolated from thymus gland extract. It modulates innate and adaptive immunity by activating dendritic cells and enhancing T-cell function. The molecule is approved as a hepatitis B treatment in many countries outside the United States (under the brand name Zadaxin) and is used investigationally in the U.S. for immune support during viral illness, post-COVID recovery, and chronic infection protocols.
- Does thymosin alpha-1 work for immune support?
- Thymosin alpha-1 has the strongest evidence base of any compounded immune peptide. It is approved internationally for chronic hepatitis B and is used adjunctively in cancer-related immunosuppression. Smaller studies and observational data support its use in post-viral recovery and stubborn-infection protocols. Effects are gradual; most protocols run at least 4 weeks before assessment.
- How is thymosin alpha-1 dosed when sick?
- Acute illness protocols typically deliver 1.6 mg subcutaneously twice weekly for 4 to 8 weeks, sometimes with a higher loading frequency in the first week (every other day). Maintenance protocols often run 1.6 mg once weekly. Optimal Balance Pharmacy compounds thymosin alpha-1 against PeptideRx prescriptions; your provider sets the protocol based on the illness pattern.
- Where do I inject thymosin alpha-1?
- Subcutaneously into the abdomen, upper outer thigh, or back of the upper arm using a 31-gauge, 5/16-inch (8 mm) needle on a U-100 insulin syringe. Sterile syringes are included with every PeptideRx shipment.
- How is thymosin alpha-1 supplied?
- Compounded by Optimal Balance Pharmacy under a 503A patient-specific prescription. Ships pre-reconstituted and ready to inject in cold-chain packaging. Every batch is tested by Eagle Analytical Services; the Certificate of Analysis is published on this product page.