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Inflammation & Immune ResearchSynthetic 28-residue N-acetylated peptide corresponding to the N-terminal fragment of prothymosin alpha

Thymosin alpha-1

Thymosin alpha-1 is studied as a synthetic 28-residue n-acetylated peptide corresponding to the n-terminal fragment of prothymosin alpha in biochemical and physiological models.

UnapprovedPreclinical Models Only (Animal / Lab)Also known as: Thymalfasin, Tα1, ZadaxinSkip to Human Evidence ↓
Other Research Areas

Thymosin alpha-1 Biological Classification

Research Record

Investigated within physiological and chemical models.

1

What is Thymosin alpha-1?

Thymosin alpha-1 is classified as a synthetic 28-residue n-acetylated peptide corresponding to the n-terminal fragment of prothymosin alpha. A synthetic 28-residue peptide with no approved drug product in the United States, though it is marketed in some other jurisdictions.

2

Why are people interested in it?

Researchers and clinicians study Thymosin alpha-1 primarily to understand its biological interactions, receptor binding affinity, and potential role within its biochemical class.

Primary Research Categories

  • Immunomodulatory peptides
  • Thymosins
3

How does it work in the body?

Thymosin alpha-1 interacts with specific cellular receptors and metabolic pathways corresponding to its structural classification as a synthetic 28-residue n-acetylated peptide corresponding to the n-terminal fragment of prothymosin alpha.

In Everyday Language: In laboratory settings, Thymosin alpha-1 interacts with specific cellular targets to modulate biological signaling pathways associated with synthetic 28-residue n-acetylated peptide corresponding to the n-terminal fragment of prothymosin alpha biology.
Cellular & Receptor Signaling: Thymosin alpha-1 interacts with specific cellular receptors and metabolic pathways corresponding to its structural classification as a synthetic 28-residue n-acetylated peptide corresponding to the n-terminal fragment of prothymosin alpha.

Biological Pathway Overview

Thymosin alpha-1 Receptor & Target Interactions

This compound is evaluated in scientific research for its interactions with target cellular receptors and signaling cascades. Consult the evidence section below for specific peer-reviewed papers.

Target Pathway

Engages specific cellular signaling cascades characteristic of its structural family.

Endocrine/Paracrine Activity

Investigated for its regulatory effects on local tissue synthesis and cellular signaling.

4

What has actually been demonstrated in humans?

Preclinical Models Only (Animal / Lab)

Evidence for Thymosin alpha-1 is currently derived primarily from laboratory or preclinical models. Consult the published evidence file for specific indexed studies.

Pharmaceutical Reality vs. Unregulated Research Chemicals

Thymosin alpha-1 is not an FDA-approved medication. Always verify chemical identity and testing documentation before interpreting research literature.

5

What is still uncertain or unknown?

Controlled human clinical trials evaluating Thymosin alpha-1 for therapeutic efficacy, safety, and pharmacokinetics are limited or absent in peer-reviewed Western registries.

Regulatory Position: Thymosin alpha-1 is an investigational or unapproved compound. It is not approved by the FDA as a commercial pharmaceutical.

Companion Resources & Guides

Evidence Landscape→

Primary research publications and study designs indexed for Thymosin alpha-1.

Research at a Glance

Open the full evidence file (3 records)

3 records in this file

  • REVIEW1
  • REGULATORY2

Publication span: 2016–2026

What Has Actually Been Studied

  • Drugs@FDA — no thymalfasin / Zadaxin record (Drugs@FDA, 2026) — Negative regulatory search.
  • FDA table of bulk drug substances nominated for compounding and subsequently withdrawn (FDA compounding communications, 2026) — Regulatory listing.
  • Immune modulation with thymosin alpha 1 treatment (Vitamins and Hormones, 2016) — Narrative review (manufacturer-affiliated authors).

What is Still Unknown

What we know

  • Marketed in some jurisdictions outside the United States (thymalfasin / Zadaxin). No Drugs@FDA approval record.
  • FDA's withdrawn nomination cites immunogenicity risk and inadequate safety information for compounding.
  • A 2016 review by manufacturer-affiliated authors summarises preclinical and clinical immune-cell findings; it is not a US label and not an independent safety assessment.

Editorial reading of the records below, labelled as Therapept analysis. How records are built

What remains uncertain

  • How non-US labelled use should be read against US compounding policy — they are different systems.

Preparation and Handling

Lyophilized peptides ship as freeze-dried powders; whatever happens next involves diluents, concentrations and storage conditions that are compound- and product-specific.

Preparation Resource HubWhat “lyophilized” meansConcentration calculator

United States Regulatory Status

No FDA-approved product

  • No record found in Drugs@FDA under thymalfasin. Not approved in the United States.
  • Listed on FDA's table of bulk substances nominated for compounding and withdrawn by the nominator.
  • FDA's published concerns state that compounded thymosin alpha-1 may pose significant risk for immunogenicity, and that available safety information is inadequate for the agency to understand the extent of any safety issues.
  • Not named on the WADA 2026 Prohibited List.
Technical Chemical SpecificationsClick to view CAS, sequence, and molecular formulas
Molecular weight
3108.3 g/mol
Sequence length
31 chars
CAS number
62304-98-7
PubChem CID
16130571
Compound class
Synthetic 28-residue N-acetylated peptide corresponding to the N-terminal fragment of prothymosin alpha
Sequence
Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN
Molecular formula
C129H215N33O55
Molecular weight
3108.3 g/mol
CAS number
62304-98-7
PubChem CID
16130571