Immune
Thymalin
A Russian thymus-extract peptide sold for immune support, with a literature that has never been independently replicated.
What it is
Thymalin is a peptide extract prepared from calf thymus, part of a Russian tradition of 'bioregulator' products. It is a mixture of short peptides rather than one defined molecule, sold for immune support and healthy ageing. It is not approved anywhere in the West, and there are no peer-reviewed controlled trials in English.
How it works
- 1
A peptide extract of calf thymus, containing a mixture of short thymic peptides rather than one defined molecule.
- 2
Proposed to support T-cell maturation and immune regulation, since the thymus is where T cells develop.
- 3
Russian research reports normalised immune markers in elderly patients.
- 4
Because the product is a mixture, its active components and doses are not standardised between batches.
- 5
No mechanism has been confirmed in controlled Western studies.
What it's studied for
Reported and studied effects
- Reported improvements in immune markers in Russian studies
- Reported fewer infections in user accounts
- No verified clinical effect in independent trials
Research protocol notes
Research context onlyResearch context only — there is no approved protocol. Russian publications describe intramuscular courses of 5–10 mg daily for 5–10 days, repeated every few months; these are not validated regimens and product composition varies by manufacturer. No human safety data from regulated trials exist.
These figures are described so you can understand what researchers did. They are not a dose, a schedule, or a suggestion — and they are not a substitute for a doctor.
Possible side effects and contraindications
Safety profile
Possible side effects
- Not systematically studied
- Injection-site reactions
- Allergic reactions to animal-derived material are possible
- Long-term safety and batch consistency unknown
Contraindications and cautions
- Not established
- Pregnancy, breastfeeding and childhood
- Autoimmune disease without specialist advice
- Competitive athletes should check anti-doping rules
A side-effect list is never complete, and these are not the only situations that warrant caution. Anything unexpected, or anything you are unsure about, should be discussed with a doctor before use.
Evidence assessment
The evidence base is Russian-language animal and small clinical work that has not been independently replicated; there are no peer-reviewed controlled trials in English.
References
- 01Thymalin thymic peptide research — PubMed search
- 02Thymus peptide extracts and immunosenescence — PubMed search
References link to published literature, regulator pages or literature indexes. Where a link points to a search, it collects the peer-reviewed work on that molecule rather than a single study.
Related
Related peptides
Other entries in Immune.
Immune
ARA-290 (cibinetide)
An erythropoietin-derived peptide that targets tissue repair rather than red blood cells; small trials, mixed results, no approval.
Immune
Ecallantide
A recombinant plasma kallikrein inhibitor for acute hereditary angioedema attacks, given under medical supervision.
Immune
Enfuvirtide
The first HIV fusion inhibitor, an injected peptide that blocks the virus from entering cells.