Sermorelin vs Thymalin
Side-by-side comparison of key properties, dosing, and research.
Growth Hormone PeptidesAnti-Aging & Longevity
SermorelinImmune SupportAnti-Aging & Longevity
Thymalin- Summary
- Sermorelin is a bioidentical synthetic peptide comprising the first 29 amino acids of naturally occurring GHRH. It is FDA-approved for diagnostic use and widely prescribed off-label for anti-aging, stimulating growth hormone production in a natural pulsatile pattern that mimics the body's own rhythm.
- 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
- 10–20 minutes
- Not well characterized as a complex extract; individual peptides have varying kinetics
- Admin Route
- SubQ
- SubQ, IM
- Research
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- Typical Dose
- 200–500 mcg
- 10 mg IM or SC daily
- Frequency
- 5–7 days per week
- Once daily
- Key Benefits
- Increases energy and vitality
- Improves body composition (more muscle, less fat)
- Enhances skin thickness and elasticity
- Strengthens immune system
- Improves sleep quality and REM sleep
- Supports bone density
- Enhances mental clarity and focus
- Safer than exogenous HGH — respects natural feedback loops
- FDA-approved for GH diagnostic use
- 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
- Injection site irritation
- Flushing
- Headache
- Dizziness
- +2 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
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