Thymosin Alpha-1 (Zadaxin) — Dosing, Cycles, Half-Life & Side Effects

Thymosin Alpha-1 (Zadaxin) is an immunomodulatory peptide with a half-life of 2-3 hours. Naturally occurring thymic peptide with immunomodulatory properties. Approved in over 35 countries for chronic hepatitis B and C and as an immune system enhancer. Enhances T-cell function and cytokine production. This page is educational harm-reduction reference compiled from peer-reviewed literature — not medical advice, not an endorsement, not a recommendation to use. Consult a licensed clinician before any decision.

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Quick Facts

Class	Immunomodulatory Peptides
Half-life	2-3 hours
Hepatotoxicity	None
Suppression	0/10

Typical Dosing Ranges

Common dose range: 1-2mg subcutaneous daily or 2-3x/week

Cycle length: 4-12 weeks

Dose ranges are compiled from published pharmacokinetic studies and community-reported usage. Where a value is community-reported rather than clinically studied, this page and its structured data flag it. Lower end of any range is always the safer starting point.

Stacking Considerations

No structural stacking blockers. Standard harm-reduction rules apply: minimize total androgen load, minimize oral exposure, and monitor bloodwork.

PCT Requirements

Never stack two SERMs. Extend a single SERM (tamoxifen OR enclomiphene/clomiphene) rather than combining.
Use the cycle planner to generate a full protocol based on your complete stack, not this compound alone.

Side Effect Profile

Not FDA approved in USA
Expensive
Requires injection
Benefits may be subtle in healthy individuals

Known Interactions

No compound-specific interactions are catalogued in the current matrix. This does not mean no risk exists — it means there is no curated pairwise entry.

Monitoring (Bloodwork & Vitals)

Comprehensive metabolic panel (baseline, mid-cycle, post-cycle)
Lipid panel (total cholesterol, HDL, LDL, triglycerides)
CBC (hemoglobin, hematocrit — watch for erythrocytosis)
Sex-hormone panel (Total T, Free T, Estradiol sensitive, SHBG, LH, FSH)
Blood pressure (weekly self-check; flag systolic >140 or diastolic >90)

Baseline bloodwork is recommended before any cycle. Discontinue if liver enzymes exceed 3× upper limit of normal or if hematocrit exceeds 54%.

Frequently Asked Questions

What is the half-life of Thymosin Alpha-1 (Zadaxin)?

Thymosin Alpha-1 (Zadaxin) has a half-life of approximately 2-3 hours. This figure is used to determine injection frequency (for esters) and post-cycle clearance timing.

What is the typical dose range for Thymosin Alpha-1 (Zadaxin)?

Commonly reported ranges for Thymosin Alpha-1 (Zadaxin): 1-2mg subcutaneous daily or 2-3x/week. Cycle length: 4-12 weeks. These are compiled from published studies and community-reported usage — individual response varies and lower end is always preferred.

Does Thymosin Alpha-1 (Zadaxin) suppress natural testosterone?

Thymosin Alpha-1 (Zadaxin) causes minimal suppression of the HPTA axis (score 0/10). PCT may still be advisable depending on stack and duration.

What is Thymosin Alpha-1 (Zadaxin) typically used for?

Thymosin Alpha-1 (Zadaxin) is commonly used for: Immune system support, Recovery from illness, Chronic infection support. Intended-use context does not imply safety — every use case carries the same underlying pharmacological risks.

Is Thymosin Alpha-1 (Zadaxin) legal?

Thymosin Alpha-1 (Zadaxin) is a controlled substance in many jurisdictions (typically Schedule III in the US when it is an anabolic androgenic steroid). StackItSmart does not provide sourcing information. Possession, import, and use without a prescription carry legal consequences that vary by country and state.

Citations

Disclaimer

StackItSmart is an independent harm-reduction reference. The content above is compiled from peer-reviewed literature and is not medical advice, not an endorsement, and not a recommendation to use Thymosin Alpha-1 (Zadaxin). Performance-enhancing compounds carry legal, endocrine, cardiovascular, and hepatic risks. Consult a licensed clinician before any decision. StackItSmart does not provide sourcing, procurement, or dosing prescriptions.