What is Thymosin Alpha-1?

01

What is Thymosin Alpha-1 made of?

The synthetic version has the sequence Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN: 28 residues with an acetyl group on the N-terminus. The reference record lists the formula C129H215N33O55 and a molecular weight of 3108.3 g/mol (PubChem CID 16130571).

The 1977 paper described it as heat-stable and highly acidic. Nearly a third of its residues are aspartic or glutamic acid.

In clinical literature the synthetic peptide is called thymalfasin.

Sources: [3] PubChem · reference structure · [1] PNAS · 1977

02

Where to buy Thymosin Alpha-1

Thymosin Alpha-1 is sold direct by Prism Labs at prismlabs.store, in 5mg vials at $49.99 per vial. The latest published lab report, tested October 26, 2026, measured 99.78% purity. Every lot’s certificate of analysis is on the product page, with a link to verify it with the testing lab.

Orders placed before 4:30 PM CT ship the same day, seven days a week, when the size is in stock. Standard shipping is free over $125. Packs of 2 or more vials are discounted, up to 18% off.

See Thymosin Alpha-1 sizes, prices and lab reports · How to vet any peptide supplier

03

Where did Thymosin Alpha-1 come from?

In the 1970s, Allan Goldstein’s group purified peptides from thymosin fraction 5. The 28-residue alpha-1 peptide was isolated and sequenced in 1977, in a paper that also proposed a naming system for the whole family.

In 1984, researchers found that in rat thymus it exists mostly as part of a larger protein, prothymosin alpha, which carries the same sequence at its N-terminus.

Sources: [1] PNAS · 1977 · [2] PNAS · 1984

04

Not the same as TB-500

Both names start with “thymosin” because both proteins were first isolated from thymus extracts, but they are unrelated. Thymosin beta-4 is a 43-residue actin-binding protein found in most cells; the alpha-1 peptide has 28 residues, a different sequence and a different research literature. TB-500 is based on thymosin beta-4, not on this peptide: What is TB-500?

Sources: [7] Journal of Biological Chemistry · 1991 · [1] PNAS · 1977

05

What has Thymosin Alpha-1 been studied for?

Research spans laboratory and clinical work:

• T-cell development and function, the original reason for studying thymus peptides.
• Immune signaling in cell and animal models.
• Blood levels in health and disease, reviewed in 2018.
• Clinical studies under the name thymalfasin, summarized in reviews from 2001 and 2020.

These are observations in laboratory models. They are not evidence about any use in people.

Sources: [1] PNAS · 1977 · [6] Expert Opinion on Biological Therapy · 2018 · [4] American Journal of Health-System Pharmacy · 2001 · [5] World Journal of Virology · 2020

06

How is Thymosin Alpha-1 supplied and stored?

Thymosin Alpha-1 ships as a lyophilized (freeze-dried) powder in 5 mg vials. The powder is stable at room temperature in transit. For lab use it is reconstituted with bacteriostatic water such as Prism H2O.

Concentration is content divided by volume: 5 mg in 2 mL gives 2.5 mg per mL. The reconstitution calculator handles other combinations.

For storage before and after reconstitution, see how to store lyophilized peptides.

07

How do I verify Thymosin Alpha-1 batches?

Every lot has its own certificate of analysis from an independent lab. Read three results separately:

• Identity: confirms the expected compound was detected.
• Purity: the share of the measured material that is the intended compound.
• Content: the amount measured, compared with the label.

Then match the lot number on your vial or bottle to the report, and use the report’s verification link to confirm it with the testing lab. Step by step: how to read a peptide COA.