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ToolsCompareGHRP-2 vs Thymalin

GHRP-2 vs Thymalin

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

Growth Hormone Peptides
GHRP-2
Immune SupportAnti-Aging & Longevity
Thymalin
Summary
GHRP-2 is a potent synthetic hexapeptide that stimulates growth hormone release by activating ghrelin receptors in the pituitary and hypothalamus. It produces one of the strongest GH pulses among GHRPs, though unlike Ipamorelin it does cause modest increases in cortisol and prolactin.
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
15–60 minutes
Not well characterized as a complex extract; individual peptides have varying kinetics
Admin Route
SubQ, Intranasal
SubQ, IM
Research
Typical Dose
100–300 mcg
10 mg IM or SC daily
Frequency
2–3 times daily
Once daily
Key Benefits
  • Strong GH pulse stimulation
  • Increased IGF-1 levels
  • Enhanced muscle growth and recovery
  • Improved fat metabolism
  • Better sleep quality
  • Increased bone density
  • Enhanced appetite (less pronounced than GHRP-6)
  • Anti-aging effects via GH axis optimization
  • 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
  • Increased appetite
  • Water retention
  • Elevated cortisol (modest)
  • Elevated prolactin (modest)
  • +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