Thymosin Alpha-1
Tα1, Zadaxin
A peptide derived from thymosin fraction 5, used clinically in several countries as an immune modulator. It has far more human data than most compounds in this library, including use as an adjunct in hepatitis and oncology settings.
- Category
- Immune & Gut
- Half-life
- Approximately 2 hours
- Cycle length
- 2–8 weeks depending on indication
- Level
- intermediate
Overview
Thymosin alpha-1 is a naturally occurring peptide produced by the thymus, where it plays a role in T-cell maturation. Unlike most compounds on this site, it has been developed as a pharmaceutical and approved in a number of countries under the name Zadaxin, primarily as an immune adjuvant. That history makes it one of the better-evidenced options in the immune category.
How it works
It acts on Toll-like receptor signalling to enhance T-cell maturation and function, increases natural killer cell activity and modulates cytokine production. The net description in the literature is immunomodulation rather than simple immune stimulation — it appears to enhance responses where they are deficient while damping excessive inflammatory signalling.
Reported benefits
- Enhanced T-cell maturation and function
- Increased natural killer cell activity
- Used clinically as an immune adjuvant in hepatitis B and C
- Adjunct use in oncology settings in some countries
- Reported reduction in infection frequency
Reported benefits describe what the published literature and user reports suggest — not a promise of outcome for any individual.
Dosing reference
Clinical use typically describes 1.6 mg subcutaneously twice weekly. Community protocols commonly use 1.5–3 mg two to three times weekly, or a shorter daily course for acute illness.
The clinical dose is standardised around the 1.6 mg figure from approved product use, which makes this one of the few compounds here with a genuinely established human dose to reference.
Clinical use in trials: 1.6 mg twice weekly by injection. Community reports stay close to that at 1.6 mg twice weekly for one to four weeks, with a minority using 900 mcg to 3 mg weekly.
These figures are what people report using in public communities. They have not been studied, verified or checked against certificates of analysis, and they are not a recommendation, a prescription or a target to aim for.
Where the reported amounts come from
Amounts are reproduced for education only. Doses from trials cannot be assumed to suit anyone else, and community-reported amounts are frequently wrong. Self-administering unapproved compounds carries serious risk.
The research picture
This is one of the better-documented peptides in the library. Randomised trials exist as an adjunct in chronic hepatitis B and C, and in several oncology settings where it has been shown to improve response rates alongside standard treatment. Evidence for general immune support in healthy people is much weaker — most of the human benefit has been demonstrated in disease contexts.
Primary sources
Preclinical & non-clinical data
A synthetic thymic peptide studied for T-cell maturation and immune modulation. It is an approved medicine in several countries for hepatitis and as a vaccine adjuvant, so its human data base is considerably better than most compounds in this index.
Non-clinical data comes from cells and animals unless stated otherwise. It answers whether a compound is worth studying in people — not whether it is safe or effective in them.
What users report
Used mainly by people managing recurrent infections or diagnosed immune conditions, and the reporting is more specific than most because people can count episodes: fewer infections, shorter illnesses, faster recovery from flares, and almost no subjective sensation from the injection itself. Some users report a mild flu-like feeling after the first doses. Because the outcomes are countable, these accounts are more useful than the average anecdote — they remain unverified personal reports, not trial data.
Where these reports come from
These are unverified personal accounts collected from public sources. They are not evidence of effectiveness or safety, they have not been independently checked, and they are not a recommendation to use anything described.
Possible side effects
- Injection-site reactions
- Transient fever or flu-like symptoms
- Muscle aches reported
- Nausea reported occasionally
Safety notes
Because it modulates immune function, it should not be used in autoimmune conditions or with immunosuppressant therapy without specialist oversight. Data in pregnancy is absent. Interactions with other immunomodulatory treatments are plausible and unstudied.
Stacking
Often seen alongside other immune-directed compounds such as LL-37 or KPV. Combining multiple immune modulators compounds the uncertainty rather than the benefit.
Related compounds
LL-37
Cathelicidin antimicrobial peptide — CAMP
Immune & Gut
A natural antimicrobial peptide with a two-sided immune reputation.
VIP
Vasoactive intestinal peptide — 28 amino acids
Immune & Gut
A signalling peptide central to immune tolerance and gut function.
KPV
Lysine-Proline-Valine
Immune & Gut
A tiny tripeptide for the gut side of inflammation.