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ToolsCompareLeuprolide vs Thymalin

Leuprolide vs Thymalin

Side-by-side comparison of key properties, dosing, and research.

Sexual Health & Libido
Leuprolide
Immune SupportAnti-Aging & Longevity
Thymalin
Summary
Leuprolide is a synthetic GnRH superagonist that, with continuous administration, paradoxically suppresses LH and FSH through receptor desensitization — the opposite effect of pulsatile GnRH. Used medically for prostate cancer, endometriosis, and precocious puberty. In men's health, short-duration use for PCT and testosterone suppression rebound.
Thymalin is a polypeptide complex isolated from calf thymus glands (developed by the Russian Gerontology Institute), shown to restore immune function, extend lifespan, and reverse thymic involution. Clinical studies demonstrate improved immune parameters and up to 40% reduction in mortality in elderly patients.
Half-Life
~3 hours (SC/IM), but depot formulations last 1–12 months
Not well characterized as a complex extract; individual peptides have varying kinetics
Admin Route
SubQ, IM
SubQ, IM
Research
Typical Dose
7.5 mg monthly, 22.5 mg 3-monthly, or 45 mg 6-monthly
10 mg IM or SC daily
Frequency
Per depot schedule
Once daily
Key Benefits
  • Medical: reduces testosterone in prostate cancer
  • Medical: suppresses estrogen in endometriosis and uterine fibroids
  • Medical: delays precocious puberty
  • Research: testosterone rebound effect after short course
  • Transgender care: hormone suppression in adolescents
  • Research: hormonal re-sensitization protocols
  • Restores thymic function and T-cell immunity
  • Extends healthy lifespan (documented in long-term studies)
  • Reduces infectious disease incidence in elderly
  • Normalizes immune parameters in immunodeficiency
  • Anti-tumor immune surveillance
  • Improves vaccine response in elderly
  • Reduces cardiovascular mortality (40% in landmark Russian study)
  • Normalizes neuroendocrine function
Side Effects
  • Hot flashes (with testosterone suppression)
  • Decreased libido and erectile dysfunction
  • Initial testosterone flare (first 1–2 weeks)
  • Bone density loss with long-term use
  • +3 more
  • Very well tolerated in decades of Russian clinical use
  • Mild injection site reactions
  • Rare: mild allergic reaction (natural extract)
  • Transient flu-like symptoms on initiation (immune activation)
Stacks With