Compare Peptides

Select any two compounds for a side-by-side comparison of mechanism, uses, risks, and FDA regulatory status.

Popular comparisons

Thymalin

Thymic peptide extract, Thymus extract

Unregulated
Immune & Longevity

Epitalon

Epithalon, Epithalone

Pending PCAC
Anti-Aging & Longevity
Overview

A thymic peptide bioregulator developed by Vladimir Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology. Thymalin is a complex of polypeptides extracted from the thymus gland that has been used clinically in Russia since the 1980s for immune restoration. Khavinson's research group reported that thymalin treatment in elderly patients was associated with reduced mortality over a 6-year follow-up period.

A synthetic tetrapeptide (Ala-Glu-Asp-Gly) originally developed by the St. Petersburg Institute of Bioregulation and Gerontology in Russia. Studied for telomere lengthening, melatonin regulation, and anti-aging properties.

Mechanism of Action

Contains a mixture of thymic peptides that restore T-cell function and thymic output. Proposed to act through epigenetic mechanisms, reactivating genes involved in immune function that become silenced with aging. May promote thymic regeneration and restore the balance between T-helper and T-suppressor cells.

Stimulates the pineal gland to increase melatonin production. Activates telomerase, an enzyme that maintains telomere length, potentially slowing cellular aging. Also reported to normalize circadian rhythms and modulate neuroendocrine function.

Common Uses
  • Immune system restoration in elderly patients
  • Post-infection immune recovery
  • Anti-aging and longevity protocols
  • Adjunct to cancer immunotherapy (in Russian clinical practice)
  • Anti-aging and longevity protocols
  • Improved sleep quality
  • Telomere length maintenance
  • Cancer prevention (preliminary research)
  • Circadian rhythm regulation
Known Risks
  • Limited Western clinical data
  • Most research from Russian institutions — peer review concerns
  • Allergic reactions possible (animal-derived extract)
  • Quality varies significantly between sources
  • Very limited human clinical data
  • Most research from Russian institutions with limited peer review
  • Long-term safety unknown
  • Injection site reactions
  • Theoretical concerns around telomerase activation and oncogenesis
Regulatory Status
Unregulated

Not FDA-approved or recognized. Used clinically in Russia and some CIS countries. No FDA category. Available only as a research peptide in the US. Khavinson's longevity claims, while published, have not been replicated in Western clinical trials.

Pending PCAC

Removed from FDA 503A Category 2 effective April 22, 2026. Scheduled for PCAC review on July 24, 2026. Most research originates from Russian institutions; limited independent Western replication. Compounding not yet authorized — status is in regulatory gray zone pending PCAC recommendation.

PCAC: July 24, 2026

This comparison is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional before starting any peptide therapy.