Peptide Knowledge Base · Immune
Thymosin Alpha-1: what it is, what the evidence says, and its real status
An immune-modulating peptide with the strongest evidence of the education-only set, but not on the PCAC agenda.
Short version: a genuinely well-studied immune peptide (approved abroad as Zadaxin), but it isn't on the US PCAC agenda, so for now it's education only here.
Can you actually get it?
Plain-English verdict: Education only.
Regulatory status: Education only (not on PCAC agenda) · Education only.
Not offered today. Thymosin Alpha-1 has solid human evidence and is approved in some countries (Zadaxin), but it is not on the US PCAC compounding agenda, so we educate only and make no availability promise.
How does Thymosin Alpha-1 work?
A 28-amino-acid peptide that modulates T-cell and innate immune function.
What it does — and what it does not do
What it does: Studied for immune modulation; used clinically abroad as an adjunct in specific conditions.
What it does not do: It is not approved or available in the US through Peptós.LIFE, and it is not on the PCAC agenda.
How honest is the evidence?
Evidence grade B — approved abroad; multiple human studies in immune contexts. Read our grading methodology for what each grade means.
What we still don't know: US regulatory path is unsettled; optimal use outside studied indications is unclear.
WADA status: Not prohibited.
How it is taken
Not offered; education only.
Who should not take it
Discuss immunosuppressive therapy and autoimmune conditions with a clinician.
Sources
Thymosin alpha-1 (Zadaxin) immune-modulation literature
Compounded medications are not FDA-approved. We keep two signals separate and never collapse them: whether you can get something, and what the rule currently says. See the live FDA Peptide Tracker or the knowledge base.
Last reviewed 2026-08-11 · Peptós.LIFE · Not medical advice.