home / compounds / Thymosin Alpha-1
Thymosin Alpha-1
Zadaxin, Tα1
REC PPT-THYMOSIN-ALPHA-1 // REV 2026-10-04 // assessment changes are logged, never silent
Immune modulator approved in several countries for hepatitis and adjuvant use.
What it is
A synthetic version of a naturally occurring thymic peptide involved in T-cell maturation.
What it does
Modulates T-cell function and innate immune signalling.
Does it work?
Approved in a number of countries (marketed as Zadaxin) for specific indications including chronic hepatitis B, which puts it well ahead of most immune peptides on evidence. General ‘immune boosting’ in healthy people is a different and weaker claim.
Claims vs data
Each marketing claim, tagged by what the evidence actually supports.
| Approved in several countries for chronic hepatitis B | supported |
| Modulates T-cell function | supported |
| Boosts immunity in healthy people | weak evidence |
Reference figures
Quoted from published reference material. These are not Peptuity recommendations.
molecular data — PubChem CID 16130571
The evidence, counted
Live counts from Europe PMC and ClinicalTrials.gov.
1,442 publications indexed, including 55 randomised controlled trials. 64 interventional studies registered. This is a well-tested compound.
SRC // EUROPE PMC + CTGOV // "Thymosin Alpha-1" // FETCHED 2026-10-04 // 1,442 RECORDS
Most-cited literature
-
[01]
Systematic review of COVID-19 in children shows milder cases and a better prognosis than adults
Ludvigsson JF. · Acta Paediatr 2020 · 1483 citations · DOI 10.1111/apa.15270
-
[02]
Review of the 2019 novel coronavirus (SARS-CoV-2) based on current evidence
Wang L, Wang Y, Ye D, Liu Q. · Int J Antimicrob Agents 2020 · 552 citations · DOI 10.1016/j.ijantimicag.2020.105948
-
[03]
Sepsis-induced immunosuppression: mechanisms, diagnosis and current treatment options
Liu D, Huang SY, Sun JH, Zhang HC, Cai QL, Gao C, Li L, Cao J, Xu F, Z · Mil Med Res 2022 · 516 citations · DOI 10.1186/s40779-022-00422-y
-
[04]
Pathogenesis of human immunodeficiency virus infection
Levy JA. · Microbiol Rev 1993 · 514 citations · DOI 10.1128/mr.57.1.183-289.1993
Common questions
Where is thymosin alpha-1 approved?
It is marketed as Zadaxin in a number of countries for indications including chronic hepatitis B and as a vaccine adjuvant — well ahead of most immune peptides.
Did it work for COVID?
It was studied during the pandemic with mixed, inconclusive results. Interest was real; a definitive answer never arrived.
Will it boost a healthy immune system?
That is a much weaker claim than its approved indications. Immune modulation in disease does not translate to enhancement in health.
Related compounds
Thymalin / Thymogen
Thymic peptide preparations from the Soviet bioregulator tradition.
LL-37
Human antimicrobial peptide. Important biology, limited therapeutic human data.
VIP
Endogenous signalling peptide with wide physiological roles.
KPV
Anti-inflammatory tripeptide fragment of alpha-MSH.