CalcMyPeptide
Anti-AgingAlso known as: Thymic Extract, Тималин

Thymalin

Thymalin is a legendary, complex polypeptide bioregulator meticulously extracted from the thymus gland. Engineered during decades of clandestine Soviet military research by Dr. Vladimir Khavinson, it is considered the ultimate biological reset button for a collapsing immune system. While Thymosin Alpha-1 acts as a targeted immune weapon, Thymalin serves as a total infrastructural builder—literally regenerating the physically involuted (shrunken) thymus gland in aging adults, vastly extending systemic longevity by restoring youthful T-cell production.

Reviewed by CalcMyPeptide Editorial Team
Last updated: April 2026Evidence: Moderate3 peer-reviewed citations

Quick Stats

Half-LifeShort (peptide mixture)
Dose Range10 mg/day for 10 days
Frequency1× daily (10-day course)
Vial Sizes10 mg
BioavailabilityIntramuscular or subcutaneous injection
Year Developed1970s

Scientific Data

Molecular Formula
Mixture of thymic peptides (<10 kDa)
Molecular Weight
Mixture (thymic extract)
PubChem ID

Mechanism of Action

Thymalin is a thymic bioregulator peptide developed by Professor Vladimir Khavinson at the St. Petersburg Institute of Bioregulation and Gerontology. It consists of a standardized extract from the thymus gland containing small regulatory peptides (molecular weight <10 kDa).

Thymalin restores thymic function in aging immune systems by promoting T-cell differentiation, maturation, and activation. The thymus involutes significantly after puberty — by age 60, most thymic tissue has been replaced by fat. Thymalin works by restoring thymic peptide signaling, rebooting T-cell production. In a landmark longitudinal study, Khavinson demonstrated that combined Thymalin + Epitalon administration in elderly patients reduced 12-year all-cause mortality by 50%. It represents the immune reconstitution pillar of the Khavinson bioregulator protocol.

Source: PMID: 15677927

Background & History

Thymalin is a polypeptide extract from the thymus gland used extensively in Russian and former Soviet clinical medicine since its development by Vladimir Khavinson in the 1970s–80s as part of the landmark Bioregulator/Peptide Bioregulator program. Unlike synthetic peptide bioregulators, Thymalin is a natural extract containing multiple short peptides. Published 15-year follow-up data (St. Petersburg Institute, 2003) demonstrated reduced overall mortality and cancer incidence in elderly subjects receiving annual Thymalin courses — one of the most compelling longevity datasets for any peptide therapy.

Research Use Cases

  • Age-related immune decline (immunosenescence) reversal
  • Post-cancer treatment immune restoration
  • Longevity protocols: reducing age-associated morbidity and mortality
  • Chronic infection susceptibility in the elderly

Dosing Protocol

Typical Dose10 mg/day for 10 days
Frequency1× daily (10-day course)
Half-Life~30 minutes
Common Vial Sizes10 mg

Dosing Protocols

Khavinson Protocol

Dose
10 mg
Frequency
Daily IM or SC for 10 consecutive days
Note: Standard Khavinson immune reconstitution protocol. Repeat 1-2 times per year. Often paired with Epitalon cycles.

Administration

Route
Intramuscular or subcutaneous injection
Timing
Morning. No fasting required.
Fasting Required?
No — food timing not critical

Expected Timeline

Day 5-10 (course)
T-cell activation markers improve. Immune resilience begins to restore.
Month 1-3 post-course
Sustained immune reconstitution. Fewer infections. Improved response to vaccines (studied in elderly).

Who Is It For?

Immune Reconstitution / Thymic Support

Moderate

Only peptide therapeutic specifically targeting involution of the thymus. 12-year mortality data (with Epitalon) is remarkable.

Longevity / Anti-Aging

Moderate

Khavinson landmark study: combined Thymalin + Epitalon reduced all-cause mortality by ~50% over 12 years.

Reconstitution Example

Vial
10 mg
Water
2 mL
Concentration
5 mg/mL
Per Unit (100u syringe)
50 mcg
Dose of 10000 mcg = 200 units on a 100-unit insulin syringe

Safety & Considerations

Used clinically in Russia and CIS countries for 35+ years with excellent safety profile. Administer intramuscularly or subcutaneously. No significant adverse events reported in clinical studies. Well-tolerated even in elderly populations.

Regulatory & Legal Status

FDA Status (US)
Research Only

Approved in Russia as Tactivin®; not FDA-approved

WADA Status (2026)
Not Listed

Not currently on the WADA 2026 Prohibited List. Policies may change — verify before competition.

Classification

Research Chemical

US Compounding: Not eligible / not available

⚠️ This information is for educational purposes only and may not reflect the most current regulatory updates. Always verify with official FDA, WADA, and jurisdiction-specific sources before use.

Interactions & Contraindications

Excellent long-term safety profile across 30+ years of Russian clinical use. May interact with immunosuppressive drugs — use under medical supervision in transplant patients. Annual 10-day cycles is the standard Khavinson protocol.

Synergies & Common Stacks

The foundational Khavinson longevity stack: Thymalin (thymic immune restoration) + Epitalon (pineal/telomere restoration). Clinical data supports this combination for mortality reduction in elderly cohorts.

Both are thymic immune modulators — Thymalin is a broader extract, Tα1 is a specific isolated peptide. May be complementary in severe immunosuppression.

Dosing Quick Reference

Thymalin— Dosing Guide
Dose Range
10 mg/day for 10 days
Half-Life
~30 minutes
Frequency
1× daily (10-day course)
Route
Subcutaneous
10 mg vial
💧 2 mL BAC water📐 5 mg/mL concentration💉 50 mcg/unit (100u syringe)
Anti-Agingcalcmypeptide.com

Frequently Asked Questions

How does Thymalin relate to Epitalon?
Both are Khavinson bioregulators. Thymalin targets the immune system (thymus restoration and T-cell reconstitution), while Epitalon targets cellular aging (telomerase activation). In Khavinson's landmark study, combining them reduced 12-year mortality by 50%.
What is the Thymalin protocol?
10 mg daily via intramuscular or subcutaneous injection for 10 consecutive days. Repeat 1-2 times per year. This cycled approach mirrors the Khavinson research protocols.

References

  1. Khavinson VKh, Morozov VG "Peptide Bioregulators and Their Role in Aging".” Neuroendocrinology Letters (2003). PMID: 14523363

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