Comparison

Thymosin Alpha-1 vs. Thymosin Beta-4

Two peptides side-by-side — identity, evidence base, legal status and known adverse events.

Identity

Mechanism of action

Thymosin Alpha-1

Thymosin Alpha-1 is an N-terminally acetylated peptide originally isolated from the thymus. It modulates T-lymphocyte maturation and function and acts on dendritic cells via Toll-like receptors (TLR9 / TLR2). In preclinical and some clinical studies, increased interferon-gamma responses and altered T-cell subpopulations have been reported.

Thymosin Beta-4

Thymosin Beta-4 forms a 1:1 complex with monomeric (G-)actin and is regarded as the principal actin-sequestering factor in many cell types, thereby influencing cytoskeletal dynamics and directional cell migration. Preclinical models additionally describe effects on endothelial cell migration and neovascularisation, as well as activation of survival signalling pathways (including ILK/Akt). The mechanistic evidence derives predominantly from cell-culture and animal models.

Evidence base

Highest evidence

Human RCT

Human trial

Studies

of which in humans

Effects recorded

Open conflicts

Documented adverse events

Legal status

Country	Thymosin Alpha-1	Thymosin Beta-4
Germany	Unapproved	Unapproved
IT	Prescription	—
United States	Unapproved	Unapproved

Full entries

Frequently asked questions

What is the difference between Thymosin Alpha-1 and Thymosin Beta-4?: Thymosin Alpha-1 is classified as "Healing", while Thymosin Beta-4 is classified as "Healing". Thymosin Alpha-1: Synthetic 28-amino-acid peptide identical to a naturally occurring thymus peptide. Approved as Zadaxin in more than 30 countries (not US/EU) for hepatitis B treatment and as an immunomodulator. Thymosin Beta-4: Thymosin Beta-4 (Tβ4) is an endogenous 43-amino-acid peptide regarded as the principal intracellular actin-sequestering factor, involved in cell migration, neovascularisation and tissue regeneration. It has been studied in dry eye, corneal and wound healing, and cardiac repair (RegeneRx programmes, RGN-259). Thymosin Beta-4 is NOT an approved drug; robust human efficacy data are limited. The grey-market TB-500 is a synthetic fragment/analogue and is distinct from it. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.
Which peptide is better supported by science, Thymosin Alpha-1 or Thymosin Beta-4?: The highest available evidence level is "Human RCT" for Thymosin Alpha-1 and "Human trial" for Thymosin Beta-4. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.
What is the legal status of Thymosin Alpha-1 and Thymosin Beta-4 in Germany and the United States?: Germany: Thymosin Alpha-1 — Unapproved, Thymosin Beta-4 — Unapproved. United States: Thymosin Alpha-1 — Unapproved, Thymosin Beta-4 — Unapproved. These are factual summaries with source and review date on the individual pages.

Country

Thymosin Alpha-1

Thymosin Beta-4

Germany

Unapproved

Prescription

—

United States

Unapproved

Frequently asked questions

What is the difference between Thymosin Alpha-1 and Thymosin Beta-4?

Thymosin Alpha-1 is classified as "Healing", while Thymosin Beta-4 is classified as "Healing". Thymosin Alpha-1: Synthetic 28-amino-acid peptide identical to a naturally occurring thymus peptide. Approved as Zadaxin in more than 30 countries (not US/EU) for hepatitis B treatment and as an immunomodulator. Thymosin Beta-4: Thymosin Beta-4 (Tβ4) is an endogenous 43-amino-acid peptide regarded as the principal intracellular actin-sequestering factor, involved in cell migration, neovascularisation and tissue regeneration. It has been studied in dry eye, corneal and wound healing, and cardiac repair (RegeneRx programmes, RGN-259). Thymosin Beta-4 is NOT an approved drug; robust human efficacy data are limited. The grey-market TB-500 is a synthetic fragment/analogue and is distinct from it. This page contrasts both neutrally and source-based — with no usage or dosing recommendation.

Which peptide is better supported by science, Thymosin Alpha-1 or Thymosin Beta-4?

The highest available evidence level is "Human RCT" for Thymosin Alpha-1 and "Human trial" for Thymosin Beta-4. A higher evidence level means more robust data, but says nothing about suitability for an individual. The full body of evidence is on each peptide's own page.

What is the legal status of Thymosin Alpha-1 and Thymosin Beta-4 in Germany and the United States?

Germany: Thymosin Alpha-1 — Unapproved, Thymosin Beta-4 — Unapproved. United States: Thymosin Alpha-1 — Unapproved, Thymosin Beta-4 — Unapproved. These are factual summaries with source and review date on the individual pages.