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.
Members only · the actionable depth
See exactly how it's run
Doses, titration structure and what to monitor are part of membership. The provenance, evidence and status above are always free.
Get the tracker · £4.99/mo →
£4.99/mo · cancel anytime
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.
Pep IQ