Thymosin Alpha-1 5mg · Tα1 — Thymic Immunomodulator · 99.3% Purity

What is Thymosin Alpha-1?

Thymosin Alpha-1 (Tα1, sold internationally as Zadaxin) is a 28-amino-acid thymic peptide and one of the most clinically validated immune-modulator peptides. It is approved in 35+ countries for chronic hepatitis B/C, immune deficiency, and as a vaccine adjuvant.

What is Thymosin Alpha-1 used for?

Research applications include CD4/CD8 T-cell maturation, NK-cell cytotoxicity enhancement, chronic viral infection adjunct therapy, immunosenescence research, and post-illness recovery. Frequently stacked with LL-37 for compound antimicrobial research and with Epitalon for combined immune + longevity protocols.

How does it work?

28-amino-acid thymic peptide; modulates T-cell maturation, NK-cell activity, and TLR signaling. Approved in 35+ countries for chronic hepatitis and immune deficiency. Read our complete research hub for the full literature review, or jump to our best peptides for immune article for comparator molecules.

Why this listing?

Tα1 has the most robust clinical literature of any thymic peptide — over 70 controlled human trials published. Lumen Labs' batch TA1-2604-A tested 99.3% purity by HPLC with full identity confirmation. Cold-chain shipping is mandatory.

How Peptide.best sources and verifies Thymosin Alpha-1

Every Thymosin Alpha-1 listing on Peptide.best comes from a verified vendor that has passed our onboarding audit — GMP-licensed manufacturing facility, documented chain of custody, third-party Janoshik Analytical testing on every batch, and a published Certificate of Analysis. Lumen Labs (the seller on this listing) currently maintains a 4.9-star average across all their products. Compare the five live offers on the right side of this page — Peptide.best forces vendors to compete on price and purity for the same SKU, so you always see the best current deal at the top, with the COA-verified purity, shipping speed, and seller rating side-by-side. Looking for alternatives in the same immune space? LL-37 and the other peptides listed under our Immune category are the most commonly compared alternatives.

Commonly stacked with

LL-37 · KPV · BPC-157 · Epitalon. See the peptide stacks page for full protocol writeups.

Compliance notice

Thymosin Alpha-1 has not been evaluated by the FDA for any indication. All statements on this page are based on published research and are not medical claims. Some products may be sold for research purposes only as marked. Consult a licensed healthcare provider before use. See our full disclaimer.

Research literature

Thymosin Alpha-1 has been the subject of growing peer-reviewed and preclinical research across the immune domain. The current PubMed index returns several hundred citations spanning mechanism, dose-response, and adverse-event reporting.

Key references commonly cited in Thymosin Alpha-1 research:

• Mechanism papers covering 28-amino-acid thymic peptide; modulates t-cell maturation, nk-cell activity, and tlr signaling. approved in 35+ countries for chronic hepatitis and immune deficiency.
• Dose-response work in rodent models (most studied species)
• Comparator-molecule trials vs. LL-37 and other peptides in the same class
• Safety / pharmacovigilance datasets where available

For a full reference list, see the Peptide.best Research Hub or the dedicated Immune pillar article.

Standard research dosing

Clinical dose: 1.6 mg subcutaneous, 2x per week (chronic hepatitis protocol). Research protocols range from 0.8–3.2 mg, 2x per week, in 4–12 week cycles.

Reconstitution

This product ships as lyophilized powder. Reconstitute with Bacteriostatic water (2mL) for stable refrigerated storage. Once reconstituted, use within 30 days; keep at 2–8°C.

Protocol notes

For full protocols and stacking guidance, see our peptide dosing guides. Always start at the low end of the published range and titrate based on individual response. Half-life (~2 hours (subcut)) determines dosing frequency.

Reported side effects

Excellent clinical safety record — occasional injection-site reaction, transient fatigue. No significant adverse events in 70+ published trials.

Contraindications

Do not use during pregnancy or lactation. Do not combine with other peptides without reviewing pharmacology. Consult a licensed healthcare provider before beginning any peptide research protocol. Discontinue immediately if any adverse reaction occurs and contact your provider.

Drug interactions

Limited interaction data exists for most research peptides. Be especially cautious when combining with prescription medications affecting the same physiological pathway as Thymosin Alpha-1 (immune pathway).

Certificate of Analysis

Every batch of Thymosin Alpha-1 sold on Peptide.best ships with a third-party Certificate of Analysis (COA) from Janoshik Analytical — the most-cited independent peptide testing lab in the research community.

Current batch testing summary

• Batch ID: TA1-2604-A
• Test date: 04/14/2026
• Peptide content (HPLC): 99.3%
• Mass-spec identity: Confirmed (target mass match)
• Endotoxin (LAL): Below detection limit
• Residual solvents: Within USP <467> limits

Download full COA PDF

For our overall testing process and chain-of-custody details, see Trust & Safety.

Q: Is Thymosin Alpha-1 legal to purchase?

A: Thymosin Alpha-1 is sold on Peptide.best for research purposes where applicable. Legal status varies by jurisdiction. See our disclaimer for full details.

Q: How long until I see effects?

A: Timing depends on protocol, dose, and individual response. Most users report observable changes within 2–6 weeks of consistent dosing per the standard research protocols. See the Dosing & Protocol tab.

Q: Can I stack Thymosin Alpha-1 with other peptides?

A: Yes — see commonly stacked peptides in the Overview tab, or browse our peptide stacks page for full protocol writeups.

Q: Why is the price lower than pharmacy retail or other research sites?

A: Peptide.best aggregates verified vendors and forces them to compete in a single checkout. Vendors save on customer-acquisition cost; the savings pass to you. Every batch is still 3rd-party COA tested.

About Lumen Labs

Lumen Labs is one of the six verified vendor partners on Peptide.best. They maintain a 4.9-star average rating across all products and submit every batch to third-party HPLC analysis before it ships.

All Lumen Labs products on Peptide.best ship from a GMP-licensed contract manufacturing facility and are tested by Janoshik Analytical. Cold-chain shipping is included on temperature-sensitive products.