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Immunephase_2_3

Thymosin Alpha-1

Thymalfasin
Immune · CAS 62304-98-7
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Category
Immune
Evidence grade
B
PubMed records
626
Female-tagged
183
Sex-analysis
4
CAS
62304-98-7
B
Evidence grade B, Phase 2/3 human trial evidence across 626 indexed studies (mixed-sex). How grades work →
Female evidence: Extrapolated
Thymosin Alpha-1: of 626 PubMed records, 183 are tagged as including female subjects and 4 carry a sex-analysis tag.Counts reflect PubMed records as of 2026-07-21. “Female” uses the Female MeSH filter and “sex-analysis” the Sex Factors MeSH filter, automated proxies pending manual study-level review. Methodology →

Overview

Thymosin Alpha-1 is a thymus-derived peptide, 28 amino acids in length, that has become a standard tool compound in immunology research. Originally identified in thymic tissue, it is now prepared synthetically for laboratory use, and its defined structure supports reproducible work in cell-culture and preclinical systems.

In research, Thymosin Alpha-1 has been studied for its relationship to T-cell maturation and differentiation and for its influence on immune-signaling pathways, including cytokine and receptor-mediated cascades. Investigators examining how the immune system regulates and coordinates responses have used it as a research material to model these mechanisms.

What makes Thymosin Alpha-1 a useful catalog entry is its long history as a reference immunomodulatory peptide with a well-studied mechanism. Whether these mechanisms translate to female physiology remains an open research question; our evidence review tracks how many of the underlying studies included women.

Summary

Thymosin alpha-1 is a 28–amino-acid immune-modulating peptide approved in several countries (as Zadaxin/thymalfasin) for chronic hepatitis B and as an adjuvant in some infections and cancers, though it remains investigational in the United States. Human trials span decades and have included women, but published analyses rarely break results out by sex, and none are designed around female-specific endpoints.

Evidence in women

Menstrual cycle
Unstudied
No study has examined dosing or response across menstrual cycle phases.
Pregnancy & lactation
Unstudied
No pregnancy or lactation safety data exist; absence of harm data is not evidence of safety.
Hormonal interactions
Unstudied
No data on interactions with estrogen, thyroid hormones, or contraceptives.
Perimenopause & menopause
Unstudied
No perimenopausal or postmenopausal study populations have been reported.
Sex differences
Unstudied
Women were enrolled in mixed-sex trials, but outcomes were not analyzed by sex, so any female-specific effect is unquantified.

Mechanism

Modulates innate and adaptive immunity, promoting T-cell maturation and dendritic-cell function, in part through Toll-like receptor signaling.

Reported dosing & routes

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We don't give dosing or medical advice. The figures below describe what was used in published research, not a recommendation. Decide with your clinician.

Reported range (literature)1.6 mg subcutaneous twice weekly in most hepatitis B trials; regimens vary by indication. Investigational in the US.
Routessubcutaneous
Female-specific dosingNot established

Contraindications: organ-transplant immunosuppression (theoretical, immune-activating)

Side effects

Reported in the research literature. Sex-specific incidence has not been separately analysed in the available records.

injection-site reactionsgenerally well tolerated in trials

Thymosin Alpha-1 reconstitution calculator

Enter this vial's amount, the bacteriostatic water you add, and a target amount to get the concentration and the U-100 syringe units to draw. Handling arithmetic for research use, not a dose recommendation.

Reconstitution

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Draw for Thymosin Alpha-1

5
units on a U-100 insulin syringe
020406080100
U-100 insulin syringe — 1 mL = 100 units
That's 0.05 mL drawn to the 5-unit mark.
Concentration5 mg/mL (5,000 mcg/mL)
Volume to draw0.05 mL
Doses per vial40

Reference chart at 5 mg/mL

Target amountVolume (mL)U-100 units
100 mcg0.02 mL2
250 mcg0.05 mL5
500 mcg0.1 mL10
750 mcg0.15 mL15
1000 mcg0.2 mL20

Research-use arithmetic only. This tool converts a vial amount, diluent volume, and a target amount into a concentration and syringe draw for laboratory handling. It is not dosing guidance, a recommendation, or a claim of safety or efficacy, and it does not account for overfill, dead space, or peptide purity. Nothing here is medical advice. “U-100” means 100 units = 1 mL; confirm your syringe graduation before measuring. See the reconstitution & storage handbook for handling detail.

Frequently asked questions

Answers drawn only from Thymosin Alpha-1's research facts and, where reviewed, its sex-disaggregated evidence. Nothing here is medical advice, dosing, or a claim of safety or efficacy.

What is Thymosin Alpha-1?

Thymosin Alpha-1, also known as Thymalfasin, is a research compound in our immune category. Thymosin alpha-1 is a 28–amino-acid immune-modulating peptide approved in several countries (as Zadaxin/thymalfasin) for chronic hepatitis B and as an adjuvant in some infections and cancers, though it remains investigational in the United States.

Is Thymosin Alpha-1 studied in women?

Thymosin Alpha-1: of 626 PubMed records, 183 are tagged as including female subjects and 4 carry a sex-analysis tag. We grade this extrapolated: women appear in the record, but no study is tagged for a sex-specific analysis, so female-relevant conclusions are inferred from mixed or male data rather than measured in women. See our methodology.

Has Thymosin Alpha-1 been studied during pregnancy or breastfeeding?

Unstudied. No pregnancy or lactation safety data exist; absence of harm data is not evidence of safety. This is not a safety clearance or a recommendation. Vera, our research chat, deliberately hard-stops on pregnancy, breastfeeding, and trying-to-conceive questions rather than answer them.

What evidence grade does Thymosin Alpha-1 have, and why?

Thymosin Alpha-1 carries evidence grade B. Phase 2/3 human trial evidence across 626 indexed studies (mixed-sex).. Grades are derived from the research record, never hand-assigned; see how grades work.

Is there a female-specific dose for Thymosin Alpha-1?

No. A female-specific dose for Thymosin Alpha-1 is not established, and this site does not provide dosing or medical advice. Any figures we show describe what published research used, not a recommendation. Decide anything about use with a qualified clinician.

How is Thymosin Alpha-1 administered in research?

In the published literature, Thymosin Alpha-1 is administered via subcutaneous. Reported dose ranges on the Dosing tab describe what studies used for laboratory research, not a protocol for people. We don't provide dosing.

What side effects have been reported for Thymosin Alpha-1?

Effects reported in the research literature include injection-site reactions, generally well tolerated in trials. Sex-specific incidence has not been separately analysed in the available records, so these are not broken out for women.

What is the CAS number for Thymosin Alpha-1?

The CAS registry number for Thymosin Alpha-1 is 62304-98-7. It is also referred to as Thymalfasin, Zadaxin, Tα1. Use it to confirm identity against a Certificate of Analysis.

How should Thymosin Alpha-1 be stored and handled?

Thymosin Alpha-1 sold for research is supplied as a lyophilized (freeze-dried) powder. Lyophilized peptides are generally kept cold and dry, at roughly -20°C for longer-term storage and 2-8°C short-term, protected from light. Once reconstituted they are typically refrigerated and used within a short window, avoiding repeated freeze-thaw cycles. This is general laboratory handling for research use only, not a directive for human use. Always follow the handling and purity details on the product's Certificate of Analysis.

Where can I buy Thymosin Alpha-1 for research?

For laboratory research use, Thymosin Alpha-1 is available from our research-use partner, Aurevena Research. Applying code research15 takes 15% off. We may earn a commission when you purchase through this link, at no extra cost to you. Products are for laboratory research use only.

Buy Thymosin Alpha-1 at Aurevena Research
Research-use supplier: Thymosin Alpha-1 is available from our research-use vendor for laboratory use. Code research15 for 15% off, applied automatically at checkout. We may earn a commission when you purchase through this link, at no extra cost to you. Products are for laboratory research use only.
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Citations (PMID)

38308608 · 11381492 · 41373628

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Educational information for laboratory and research use only. Not medical advice, a recommendation, or a claim of safety or efficacy; no personal dosing. “Unstudied” means no qualifying study was found, not that a compound is safe or unsafe.