Thymosin Alpha-1
A 28-amino-acid immunomodulatory peptide approved in many countries (as Zadaxin) for hepatitis B and as an adjunct in cancer and infection.
In plain English
Thymosin alpha-1 (Tα1) is a naturally occurring 28-amino-acid peptide first isolated from the thymus gland. As the drug Zadaxin, it is approved in more than 30 countries — including Italy and several Asian and Latin American nations — for chronic hepatitis B and as an immune adjuvant in cancer care, severe infection, and post-transplant settings. It is not approved by the U.S. FDA. Mechanistically, Tα1 modulates T-cell maturation and function, dendritic cell activity, and innate immune signaling. People commonly research thymosin alpha-1 for immune support, recovery from infection, and adjunctive cancer care.
What it is
Thymosin alpha-1 is a 28-amino-acid synthetic peptide identical in sequence to a naturally occurring thymic peptide.
Mechanism (summary)
Tα1 modulates T-cell maturation, increases Th1 cytokine responses, supports dendritic cell function, and engages TLR-9 signaling. Net effect is broad immunomodulation rather than simple immune stimulation.
Why people research it
- Chronic hepatitis B
- Adjuvant immune support in cancer therapy
- Severe infection and sepsis
- Immune recovery in transplantation
Human evidence
Multiple RCTs and meta-analyses support efficacy in chronic hepatitis B (especially combined with interferon) and as an adjuvant in select cancers. Trials in COVID-19 and severe sepsis have shown mixed but generally favorable signals.
Animal / lab evidence
Animal models support immunomodulatory effects across infection and cancer settings.
Key studies
Each summary explains the design, what was found, and what it doesn't prove.
Pooled across trials, more chronic hepatitis B patients cleared the virus with thymosin alpha-1 than with control treatments.
Hospitalized severe COVID-19 patients who received thymosin alpha-1 had lower mortality than matched comparison patients.
History
Originally isolated from calf thymus in the 1970s by Allan Goldstein. Synthetic Tα1 (Zadaxin) was developed by SciClone Pharmaceuticals.
PeptidePedia is for educational and informational purposes only. We do not sell peptides, prescribe peptides, provide medical advice, or recommend treatment. Peptides may not be approved for human use except in specific legal prescription or clinical contexts. Always consult a licensed medical professional before making health decisions.
Related peptides
A synthetic fragment of thymosin beta-4 studied in animals for wound healing, cardiac repair, and tissue regeneration.
A human cathelicidin antimicrobial peptide central to skin and respiratory innate immunity.
The C-terminal tripeptide of α-MSH studied for anti-inflammatory effects in gut and skin disease.