Thymalin
A thymic peptide complex studied for immune reconstitution and longevity, shown to reduce mortality in elderly populations in long-term Russian clinical trials.
Also known as: Thymulin analog, Thymic peptide extract
Regulatory Status
Classification date: 2026-02-27
Reclassification to Category 1 announced but not yet formalized
Compounding: Not currently available for compounding
Evidence Summary
How It Works
Thymalin is a polypeptide complex isolated from calf thymus glands. It restores T-cell-mediated immunity by promoting T-cell differentiation and maturation in the thymus. In combination with epithalamin, it demonstrated a significant reduction in mortality over a 12-year follow-up in elderly patients. It modulates neuro-immuno-endocrine interactions and has been shown to normalize immune biomarkers in immunosuppressed individuals. Its mechanism overlaps with but is distinct from thymosin alpha-1.
Common Applications
Safety & Considerations
Well tolerated in Russian clinical trials spanning decades. Injection-site discomfort is the most commonly reported side effect. Sourced from animal thymus tissue in its original formulation, raising concerns about batch consistency and potential immunogenic reactions. Synthetic alternatives are preferable. Limited Western clinical data. Currently not legal for compounding in the US.
Regulatory classifications can change rapidly. The information shown here was last verified on 2026-02-27. Always confirm current legal status with a licensed provider or the FDA before making treatment decisions.