Thymosin Alpha-1 5mg

Thymosin alpha-1 is a 28-residue peptide, acetylated at its N-terminus, first purified from calf thymus and known in synthetic form as thymalfasin. This listing is the 5 mg vial of freeze-dried powder, the main fill; a 10 mg vial is also sold. Research on the peptide concerns immune regulation, from dendritic cell activation in cell and mouse studies to clinical trials in viral hepatitis, sepsis and other infections.

Specifications

Fills in this range

Thymosin Alpha-1 is sold in 2 fills. The compound and the testing are the same in every fill; only the amount in the vial changes.

Sequence and molar amount

The certificate gives the sequence as Ac-SDAAVDTSSEITTKDLKEKKEVVEEAEN-OH: 28 residues, with an acetylated serine at the N-terminus and a free carboxyl on the C-terminal asparagine. The chain is rich in glutamate, aspartate and lysine and has no aromatic residues, cysteine or methionine. The formula is C129H215N33O55 and the theoretical mass 3108.3 Da, the number to set against the LC-MS identity result on the lot certificate.

At that mass, 5 mg is about 1.6 µmol, a little less once the certificate’s water content is allowed for. Dissolved in 2 mL, the vial gives a solution of roughly 0.8 mM. Thymosin alpha-1 and thymosin beta-4, which PrymaLab sells as TB-500, are separate peptides with separate literatures despite the shared name.

What the research covers

Origin

Low and colleagues reported the isolation, characterisation and biological activities of thymosin alpha-1 from calf thymus in 1979¹. It came to be described as a thymus-derived biological response modifier, and a synthetic version was the first of the thymosins to reach clinical use². Camerini and Garaci’s 2015 review described it as a peptide that activates and regulates various cells of the immune system³.

Mechanism in cell and mouse studies

The most detailed mechanistic paper in this set is a 2004 study by Romani and colleagues on dendritic cells and the mould Aspergillus fumigatus⁴. Thymosin alpha-1 induced functional maturation and interleukin-12 production in fungus-pulsed dendritic cells, through a p38 MAP kinase and NF-kB-dependent pathway that signalled via MyD88 and involved distinct Toll-like receptors⁴. In mice the synthetic peptide activated Th1-dependent antifungal immunity and sped the recovery of myeloid cells, and it protected highly susceptible mice that had received haematopoietic transplants from aspergillosis⁴. The authors proposed it as a candidate adjuvant that coordinates innate and adaptive immune responses to the fungus⁴.

Clinical use and trials

Unlike most research peptides, thymosin alpha-1 has a licensed history: a 2009 review by Goldstein and Goldstein reported it approved in over 35 countries for hepatitis B and C and as an immune stimulant and adjuvant, and in late-stage testing in the United States and Europe for hepatitis C and stage IV melanoma². The same review described newer trials in septic shock, acute respiratory distress syndrome, peritonitis, acute cytomegalovirus infection, tuberculosis, severe acute respiratory syndrome and lung infections in critically ill patients, and an emerging role as a chemoprotective agent during chemotherapy². Camerini and Garaci reviewed trials in hepatitis B and C, sepsis and aspergillosis after bone marrow transplantation, together with its use as a vaccine enhancer, and wrote that it had been given to thousands of patients with a safety profile they called excellent³.

What is not established

This page cites reviews of the clinical work rather than the individual trials, so it gives no effect sizes²,³. Camerini and Garaci themselves wrote that, despite wide use, several questions had not been properly addressed, including the amount and timing of treatment, combination treatments and the end-points trials should measure³. The dendritic cell mechanism rests mainly on one group’s fungal infection models⁴. Approval abroad reflects regulators’ decisions about the licensed drug product, not about research material, and none of these studies used PrymaLab material. The individual hepatitis, sepsis and cancer studies are covered in the thymosin alpha-1 guide, and the guide to peptides for injury recovery explains why it is grouped with immune peptides rather than tissue-repair ones.

How each lot is tested

Every lot is tested in PrymaLab’s own laboratory in Ashland, Kentucky before release: RP-HPLC for purity, LC-MS for identity, Karl Fischer titration for water, LAL for endotoxin and USP <71> for sterility. The results for the lot now shipping are in the certificate panel on this page, and the certificate number, key and QR code can be checked on the verify page. These are in-house results from PrymaLab Analytical, not an independent test, and the lab is not accredited to ISO 17025. The third-party testing guarantee on this page still applies: if any independent laboratory finds the wrong compound, or less than the stated purity or amount, the order is refunded and the cost of the test is reimbursed.

Frequently asked questions

References

1. Low T, Thurman G, McAdoo M, et al. The chemistry and biology of thymosin. I. Isolation, characterization, and biological activities of thymosin alpha1 and polypeptide beta1 from calf thymus. Journal of Biological Chemistry. 1979;254(3):981-986. DOI
2. Goldstein AL, Goldstein AL. From lab to bedside: emerging clinical applications of thymosin alpha 1. Expert Opin Biol Ther. 2009;9(5):593-608. DOI · PubMed
3. Camerini R, Garaci E. Historical review of thymosin α 1 in infectious diseases. Expert Opin Biol Ther. 2015;15 Suppl 1:S117-27. DOI · PubMed
4. Romani L, Bistoni F, Gaziano R, et al. Thymosin alpha 1 activates dendritic cells for antifungal Th1 resistance through toll-like receptor signaling. Blood. 2004;103(11):4232-9. DOI · PubMed