Thymalin
Thymalin is a thymic peptide bioregulator extracted from calf thymus, studied for immune restoration and age-related immune decline; research protocols typically use 2 mg daily subcutaneously in short repeated courses of several consecutive days.
Best for
It has been studied primarily for immune restoration and modulation, age-related decline of thymic and immune function, and as a candidate geroprotective (longevity-oriented) bioregulator in older adults.
What to expect
Pharmacokinetic research reports rapid distribution to lymphoid tissue within roughly 90 minutes of subcutaneous injection, while the immune and geroprotective endpoints studied are assessed over weeks to years of repeated annual courses.
Pairs with
In longevity-oriented research it is most often paired with the pineal peptide Epithalamin/Epitalon, and it is sometimes discussed alongside other thymic peptides such as Thymosin alpha-1.
Research and the original clinical work have typically used subcutaneous or intramuscular administration in short repeated "courses" (commonly cited as roughly 5-10 mg daily for several consecutive days, repeated periodically rather than dosed continuously).
- How often
- Daily
- When
- Morning
- Route
- Subcutaneous
- Vial & water
- 10 mg vial in 1 mL = 10 mg/mL · 5 mg = 50 units on a U-100 syringe
- Cycle
- 3–10 day course (10 days in the Khavinson studies), repeat every 1–6 months
The same numbers the goodtides app and the Dose Calc use — a research reference, not a prescription. Responses are individual; research protocols start at the low end.
Thymalin is a thymic peptide bioregulator: a polypeptide extract isolated from the thymus gland of young calves, comprising a heterogeneous mixture of short acidic peptides (roughly 1-10 kDa) rather than a single defined sequence. It was developed in Russia by Vladimir Khavinson and colleagues as part of the "peptide bioregulator" class.
Thymalin is not FDA-approved; outside of its regulatory status in Russia it is handled as a research compound, and the geroprotective and immune-restoration findings come largely from a single research group and remain to be independently confirmed in large modern trials.
Research characterizes it as immunomodulatory: it has been studied for its proposed role in regulating T-lymphocyte differentiation and maturation, modulating CD4+/CD8+ cell populations, and influencing the balance of cytokines such as IL-1β, IL-6, and TNF-α. More recent work attributes some activity to short dipeptide constituents (e.g., KE and EW) acting at the level of gene expression and protein synthesis in immune cells.
- Half-life
- Not well characterized in humans (short-lived peptide mixture)
- Peak
- Distributes to lymphoid tissue ~90 min post-SC
- Absorption
- Parenteral (SC or IM); peptides degraded if taken orally
- Bioavailability
- Low/negligible oral; parenteral route used in research
References2
Log every dose, count every vial, and verify your batches — free in the goodtides app.
This page is educational reference material about compounds studied in research settings. It is not medical advice, and nothing here is a recommendation to buy, possess, or use any compound. Research findings described are from published literature; individual compounds may not be approved for human use. Talk to a licensed clinician about anything that affects your health.