Immune modulationThymic peptidesApproved abroad (Tα-1)
Thymic Foundation
Stack: Thymosin α-1 + Thymalin · the thymic base of the immune section
"Thymosin α-1 is the best-characterised immune peptide there is — an approved medicine (Zadaxin) in 35+ countries. Thymalin is an older thymic bioregulator with far thinner evidence. Honest framing: the credibility of this stack rests almost entirely on Tα-1, and on its approved indications rather than general biohacking immune support."
GoalImmune modulation / resilience
Compounds2 · Tα-1 + Thymalin
Human evidenceModerate — Tα-1 approved abroad, decades of RCTs; Thymalin limited
StatusTα-1 (thymalfasin / Zadaxin): approved in 35+ countries for hepatitis B/C & immune support — NOT FDA/MHRA/EMA-approved. Thymalin: unlicensed. UK: neither is a licensed medicine here
In this stack — snapshot; tap through for the full molecule file
Provenance & evidence layers — of the combination, not the parts
Approved clinical use (abroad)
Thymosin α-1
As thymalfasin (Zadaxin), approved in 35+ countries — China, Italy, India and others — for chronic hepatitis B and C, immunodeficiency, and as a chemotherapy adjunct. Typical regimen 1.6 mg SubQ twice weekly.
Thymalin
Used historically in Russian clinical practice as a thymic bioregulator; no Western marketing authorisation.
Evidence it adds
Genuine regulator-grade standing abroad for Tα-1 — unusual for this catalogue.
Basis: thymalfasin approvals in 35+ countries
Clinical trial evidence
Thymosin α-1
Decades of RCTs (notably chronic hepatitis B virological response); the best-characterised immune peptide in clinical use. Note: the 2025 TESTS phase-3 sepsis trial (BMJ, ~1,106 patients) missed its primary endpoint.
Thymalin
Mostly older Russian studies (Khavinson group); immune-restoration and longevity claims have not been independently replicated at scale.
Evidence it adds
Moderate–strong for Tα-1 in its studied indications; weak for Thymalin.
Basis: peer-reviewed RCTs (Tα-1) · older Russian studies (Thymalin)
Grey-market / unsupervised use
Where / who
Both are sold as research peptides for "immune support" — a use that extends well beyond Tα-1’s approved indications.
What changes
General immune-support use is extrapolation; product purity and identity are unverified. Note the FDA restricted Tα-1 compounding access in 2023.
Evidence it adds
None on the biohacking use — the approved evidence is for specific diseases.
Basis: real-world sourcing — not a trial tier
Regulatory — read carefully
MHRA (UK)
Neither is a licensed UK medicine and neither is a controlled drug — unlicensed here. Tα-1 is a prescription medicine where it is approved abroad.
FDA (US)
Tα-1 not approved (holds Orphan Drug designation for some indications); compounding access restricted since 2023.
What it means
The safety and efficacy record belongs to the approved product used for approved indications — not to grey-market immune-support use.
Basis: MHRA: unlicensed · FDA: not approved (orphan designation)
Why this is the foundation
Thymosin α-1 is the base here because it is, unusually for this catalogue, a genuinely approved and deeply studied medicine — the immune peptide with the strongest clinical record by a wide margin. Thymalin is the older bioregulator add whose evidence is far thinner and largely Russian. The honest framing: this stack’s credibility rests on Tα-1, and specifically on its approved indications — hepatitis and immune reconstitution — rather than the general "immune support" use most people are actually reaching for, which is extrapolation.
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Cycle shape — how it's typically structured, not a schedule to follow
Tα-1
SubQ, twice weekly (course)
Tα-1’s studied regimen is 1.6 mg subcutaneously twice weekly in courses (the Zadaxin hepatitis schedule); Thymalin is typically a short intramuscular course. These are the studied patterns, not a prescription to follow.
What's worth monitoring
Thymosin α-1 has a strong safety record across decades of clinical use — adverse events are typically mild and transient. The honest caveats are regulatory and evidential: it is not UK-licensed; the 2025 phase-3 sepsis trial was negative; and general "immune support" use sits outside its approved indications. As an immunomodulator, it should be approached cautiously by anyone with autoimmune disease or on immunosuppression. Baseline bloods and a clinician conversation are the floor. General information, not medical advice.
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