What is Thymosin Alpha-1 used for in research?

Thymosin Alpha-1 (thymalfasin) has been studied primarily for immune modulation. Research contexts include chronic hepatitis B and C, immune reconstitution in immunocompromised populations, sepsis, and as an adjuvant to vaccines. It is approved in more than 35 countries as Zadaxin for these indications, though it is not FDA-approved in the United States.

Is Thymosin Alpha-1 FDA-approved?

No. Thymosin Alpha-1 is not FDA-approved in the United States. It is approved and marketed as Zadaxin (thymalfasin) in over 35 countries, primarily for chronic hepatitis B, chronic hepatitis C, and as an immune enhancer. In the US it is available only through research channels and off-label compounding pharmacies.

How is Thymosin Alpha-1 different from Thymosin Beta-4 (TB-500)?

They share the 'thymosin' name but are unrelated peptides with different structures and mechanisms. Thymosin Alpha-1 is a 28-amino-acid immunomodulator that acts on Toll-like receptors and T cells. Thymosin Beta-4 (and its research analog TB-500) is a 43-amino-acid peptide investigated primarily for cell migration, angiogenesis, and tissue repair. They are studied in entirely different research contexts.

How do you reconstitute Thymosin Alpha-1?

Add bacteriostatic water slowly down the side of the vial and swirl gently — do not shake. A common ratio is a 5 mg vial with 2 mL BAC water, producing 2.5 mg/mL. Use the free calculator to convert your specific vial size and target dose into an exact syringe draw.

How should Thymosin Alpha-1 be stored?

Store lyophilized vials at -20°C for long-term storage or refrigerated (2–8°C) for short-term. After reconstitution, refrigerate at 2–8°C and use within 14–28 days. Protect from light and avoid freeze/thaw cycles once in solution.

RESEARCH PROTOCOL

Thymosin Alpha-1: Dosage, Calculator & Reconstitution Guide

Thymic peptide studied for immune modulation — research context only.

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What Is Thymosin Alpha-1?

Thymosin Alpha-1 (TA1, thymalfasin) is a 28-amino-acid peptide naturally produced by the thymus, first isolated in 1977 from thymosin fraction 5. It is one of the most-studied immunomodulatory peptides, with a body of clinical literature spanning several decades.

Its proposed mechanism centers on modulation of both innate and adaptive immunity. TA1 binds Toll-like receptors (TLR-2, TLR-4, and TLR-9) on dendritic cells and T cells, promoting T-cell maturation, dendritic cell activation, and cytokine production (including IFN-γ and IL-2). It has been characterized in the literature as a pleiotropic immune modulator rather than a stimulator or suppressor.

Regulatory status is important to state clearly: Thymosin Alpha-1 is approved in more than 35 countries as Zadaxin for chronic hepatitis B, chronic hepatitis C, and as an immune enhancer. It is not FDA-approved in the United States. In the US it is used only in research and through off-label compounded formulations.

This is a research-summary page. Nothing here constitutes a health claim or medical recommendation.

Common Research Doses

Typical vial size	BAC water volume	Common dose range	Typical frequency
5 mg	2 mL	1.0–1.6 mg	2–3× weekly
10 mg	2 mL	1.0–1.6 mg	2–3× weekly

The 1.6 mg dose reflects the approved Zadaxin regimen for chronic hepatitis indications outside the US. Research protocols vary.

Reconstitution Reference

Reconstitution is the process of dissolving lyophilized peptide powder in bacteriostatic water. Add BAC water slowly down the side of the vial, swirl gently until fully dissolved, and do not shake. Once reconstituted, store refrigerated.

Vial size	BAC water	Concentration	Doses at 1.0 mg	Doses at 1.6 mg
5 mg	2.0 mL	2.5 mg/mL	5 (at 1.0 mg)	3 (at 1.6 mg)
10 mg	2.0 mL	5.0 mg/mL	10 (at 1.0 mg)	6 (at 1.6 mg)

Compare all peptides on the Peptide Dosage Chart.

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Storage & Stability

Item	State	Recommendation
Lyophilized vial	Sealed powder, unopened	Store at -20°C long-term; refrigerate for short-term
Reconstituted vial	In BAC water solution	Refrigerate at 2–8°C; use within 14–28 days
Bacteriostatic water	Multi-use vial	Room temperature; discard 28 days after first puncture
Light exposure	Any form	Protect from direct light; store in original box

Sourcing

Recommended Supplier

PSPeptides carries third-party tested, research-grade Thymosin Alpha-1 with published COAs.

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Peptide Calculator →

Exact syringe draws for any vial + dose.

Peptide Dosage Chart →

Reconstitution reference across compounds.

Related thymosin-family peptide: TB-500 (Thymosin Beta-4) — different structure, different research context.

Frequently Asked Questions

Disclaimer: The information on this page is provided for research and educational purposes only. Thymosin Alpha-1 is not FDA-approved in the United States. Nothing on this page constitutes medical advice. Consult a qualified healthcare professional before making any health-related decisions.