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Tier C Immune

Thymalin

Thymus-Derived Peptide Complex — Polypeptide Bioregulator

Thymus-derived immunomodulatory peptide mixture — used in Russian longevity medicine alongside Epitalon for immune restoration.

Tier C — Early or Mixed: Limited human trials; effect size uncertain. How our tiers work →

Research facts

Half-lifeVariable (mixture)
RouteIM
Typical dose10–20 mg/cycle
Frequency10 days (standard Khavinson protocol)
SolventCommercial IM preparation
pHN/A
StabilityRefrigerated

Mechanism of action

Thymalin is a polypeptide preparation extracted from bovine thymus glands, standardised by the Russian Khavinson research group. It contains multiple immune-regulatory peptides including Thymopentin, Thymulin, and related sequences that modulate T-cell maturation, differentiation, and function. The thymus involutes significantly with age — Thymalin is hypothesised to partially restore thymic-dependent immune function. In the landmark Khavinson longevity study, elderly patients given Thymalin + Epitalon for 2–3 years showed significantly reduced mortality (76% of control group died vs. 41% in treatment group) over a 6-year follow-up period.

Documented effects (research-model)

  • T-cell maturation and immune function restoration
  • Landmark Khavinson study: significant mortality reduction in elderly
  • Thymic-dependent immunity restoration in immunosenescence
  • Combined with Epitalon in standard longevity protocol

Research protocols

ProtocolDoseFrequencyCycleVial
Khavinson Protocol 10 mg IM daily × 10 days Daily × 10 days per cycle 10 days, repeated 1–2× per year Commercial Thymalin preparation

Research context only. Not medical advice. Consult a qualified healthcare professional before any protocol decision.

Synergies

  • Epitalon HIGH
    The Khavinson Longevity Stack — Epitalon (pineal/telomere) + Thymalin (thymic/immune) is the foundational protocol from the Khavinson studies showing mortality reduction.

Myths & misconceptions

Myth Thymalin is the same as Thymosin Alpha-1.
Reality Thymalin is a polypeptide mixture from bovine thymus (contains multiple peptides); Thymosin Alpha-1 is a single, defined 28-amino acid peptide. Both modulate thymic immune function but are distinct compounds with different pharmacological profiles and evidence bases.

Evidence gaps

  • The mortality data comes from small Russian studies with methodological limitations.
  • No Western RCT replication of the longevity findings.
  • Active ingredient identification is incomplete (mixture preparation).

Safety notes

Generally well-tolerated in Khavinson studies. IM administration. Bovine-derived — theoretical prion disease concern (extremely low risk, standard pharmaceutical sourcing protocols apply). Research context only.

Biomarkers to monitor

Full Blood CountWBC differentialT-cell subsets (CD4/CD8 ratio)Cortisol

Primary-source citations

  • PMID 12487682 — Thymalin and Epitalon in the treatment of aging and longevity in elderly subjects (Neuro Endocrinol Lett. 2003)

Frequently asked

What is Thymalin?

Thymalin (Thymus-Derived Peptide Complex — Polypeptide Bioregulator) is a research compound classified in our library as Tier C — Limited human trials; effect size uncertain.. Thymus-derived immunomodulatory peptide mixture — used in Russian longevity medicine alongside Epitalon for immune restoration.

What is the evidence tier for Thymalin?

We classify Thymalin as Tier C: Limited human trials; effect size uncertain. See our full peptide evidence tiers explainer for how we assign S/A/B/C/D.

What is the research dose of Thymalin?

For Thymalin, typical research dose is 10–20 mg/cycle, route is IM, half-life is Variable (mixture). Protocols vary by research goal — see the protocols section on this page for standard and advanced dosing schedules. Research use only, not medical advice.

What does Thymalin stack well with?

Thymalin stacks well with Epitalon. The Khavinson Longevity Stack — Epitalon (pineal/telomere) + Thymalin (thymic/immune) is the foundational protocol from the Khavinson studies showing mortality reduction.

Is Thymalin safe?

Generally well-tolerated in Khavinson studies. IM administration. Research context only — no compound on this site is approved for human therapeutic use unless explicitly noted.

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