Thymosin Alpha-1

Also known as: Tα1, Zadaxin

Moderate evidence
ClassImmunomodulatory thymic peptide
Research statusApproved in several countries
Independent tests2
Studies indexed3
Companies tested 2

Overview

A thymic peptide used clinically in parts of Asia and Europe as an immune modulator, particularly alongside hepatitis treatment.

Thymosin Alpha-1 is classified as an immunomodulatory thymic peptide. Its current development status is: approved in several countries. Human trial data exists but is limited in size, duration or independence; conclusions should be held loosely.

The Peptide Institute tracks Thymosin Alpha-1 because it is actively sold through research-compound and telehealth channels. Our interest is narrow and specific: what is actually in the vial, whether the label is accurate, and whether the sellers of it can document what they claim. We take no position on whether anyone should use it.

Independent Testing

Independently tested companies that sell Thymosin Alpha-1

Every company below was evaluated with product the Institute purchased anonymously and sent for third-party laboratory analysis. Ranked by Index Score™.

Companies
2
Samples
2
Updated
Jun 17, 2026
  1. 1 Apex Peptides Exceptional Institute
    Top Rated     Thymosin Alpha-1

    99.2% average purity across 1 sample

    Purity & Testing 99 Transparency 90 Samples 1 91 View company
  2. 2 Sterling Compound Co. Good

    98% average purity across 1 sample

    Purity & Testing 91 Transparency 66 Samples 1 74 View company
Compare all tested Thymosin Alpha-1 companies

Research & Studies

Studies library

  • Mechanistic characterization of Thymosin Alpha-1 receptor binding

    Frontiers in Pharmacology · Meta-analysis · Dec 14, 2017

    Adds to the Thymosin Alpha-1 evidence base without resolving the central question of human efficacy.

  • Thymosin Alpha-1: dose-ranging efficacy and safety findings

    Frontiers in Pharmacology · Randomized controlled trial (Phase 3) · Aug 2, 2014

    Adds to the Thymosin Alpha-1 evidence base without resolving the central question of human efficacy.

  • Thymosin Alpha-1 in preclinical models: efficacy and translational limits

    Cell Metabolism · In vitro characterization · Jun 13, 2013

    Characterises Thymosin Alpha-1 activity in a controlled setting. Endpoints are surrogate measures rather than clinical outcomes.

Independent Testing

Testing database

Laboratory verification of Thymosin Alpha-1 products across the companies we index.

Thymosin Alpha-1 Apex Peptides
Purity 99.2% Verified
Thymosin Alpha-1 Sterling Compound Co.
Purity 98.0% Verified

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