Thymalfasin · Thymosin Alpha-1 · TA1 · Zadaxin
Thymosin Alpha-1 (TA-1) is a 28-amino acid peptide naturally produced by the thymus gland that plays a central role in adaptive immune function. It is one of the few peptides with FDA/international regulatory approval, marketed as Zadaxin in over 30 countries for the treatment of hepatitis B, hepatitis C, and as an immune adjuvant in cancer therapy and vaccination protocols. TA-1 enhances T-cell maturation, natural killer cell activity, dendritic cell function, and cytokine production. It bridges innate and adaptive immunity by promoting the differentiation of immature T-cells into functional CD4+ and CD8+ effector cells. TA-1 is discussed in longevity, immune optimization, and chronic infection protocols as one of the best-characterized immune-modulating peptides available.
Starting dose. 1.6 mg — Zadaxin standard dose
Any time of day. No fasting required. Continuous use safe at 2x/week. For acute immune challenge, daily dosing for 5-7 days.
Start here. Every protocol below is ordered lowest-first. Begin at the smallest effective dose, hold about a week to assess tolerance, and step up only if needed.
TA-1 acts on thymic progenitor cells to promote T-cell differentiation and maturation. It activates toll-like receptors (TLR2, TLR9) on dendritic cells, enhancing antigen presentation to T-cells. TA-1 increases production of IL-2 and IFN-alpha, key cytokines for T-cell proliferation and antiviral defense. It promotes CD4+ helper T-cell and CD8+ cytotoxic T-cell differentiation, enhances natural killer cell cytotoxicity, stimulates dendritic cell maturation for improved antigen presentation, and modulates Th1/Th2 balance toward appropriate immune responses. TA-1 also opposes immune senescence (the age-related decline in thymic function and T-cell diversity) by partially restoring thymic output in aged individuals.
Days 1-7: No immediate subjective effects expected. Immune cell changes begin at the cellular level.
Weeks 2-4: T-cell maturation and NK cell activation become functionally relevant. Immune resilience begins to improve. Lab markers may show changes.
Weeks 4-12: Full immune optimization. Reduced frequency and severity of infections. Vaccination responses enhanced. Best assessed through immune panel labwork.
Each reference below was re-fetched from its PubMed record, and the quoted sentence was confirmed to appear in that abstract and to support the claim it sits under. Follow any of them to read the source.
Exact-molecule evidence boundary: the live abstract reports the quoted finding for TA-1; no broader inference is made.
Thymalfasin (thymosin alpha-1; Talpha1) is a 28-amino acid polypeptide that has shown efficacy in the treatment of chronic hepatitis B virus (HBV) infection.
Evidence scope. Exact molecule wording appears in the quoted live sentence. Only the population/model, formulation, route, and outcome expressly stated there are supported.
Claims we could not support
No abstract we checked supports these for this molecule at this route. That is not the same as saying they are false — it marks where the evidence is missing.
Dose/route: 1.6 mg (Zadaxin standard dose); SubQ injection; 2-3 times per week or daily for intensive protocols. No selected live abstract sentence verified this complete regimen.
Mechanism as written in source JSON. No selected live abstract sentence verified the complete mechanism at the card formulation/route and relevant population/model.
Primary safety claim as written in source JSON. No selected live abstract sentence verified the complete safety claim for this exact formulation and route.
Immune enhancement
Strongest claim. FDA/international approval as immune adjuvant. Phase 3 clinical trial data. One of the only peptides with this level of regulatory validation for immune claims.
Approved as adjuvant in melanoma treatment in several countries. Clinical data supports improved outcomes when combined with standard cancer treatments. Not a standalone cancer treatment.
Thymic involution is a hallmark of aging. TA-1 partially restores thymic output. Conceptually sound for immune aging but not studied in longevity-specific trials.
Two different questions: what is documented about running these together, and what is documented about drawing them into the same syringe. A good pharmacological partner can still have to be pinned separately.
Check any specific pair in the Stack & Interaction Checker, which answers both questions separately. Absence of a documented conflict is not evidence of safety.
SubQ
Immune cell maturation and cytokine effects persist well beyond plasma clearance
Enzymatic degradation and renal excretion
Storage. Store unreconstituted vials frozen (-20C) or refrigerated (2-8C). After reconstitution with BAC water, refrigerate at 2-8C. Stable for 28-30 days. FDA-approved formulation has well-characterized stability. Protect from light.
Approved as Zadaxin in over 30 countries for hepatitis B/C treatment and as immune adjuvant. Not FDA-approved in the United States (application was filed but not pursued commercially). WADA does not specifically prohibit TA-1. Available through compounding pharmacies and research channels.
Put it to work
Open TA-1 straight into OnePin with your vial and dose pre-filled, then let it handle the syringe math and remind you before the vial runs out.
Open TA-1 in the app →Go deeper
The complete TA-1 walkthrough, real protocol discussion and coaching live inside the BlessUp community on Skool.
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