Spermidine vs Somatropin (HGH)
Side-by-side comparison of key properties, dosing, and research.
Anti-Aging & LongevityCognitive Enhancement
SpermidineGrowth Hormone PeptidesAnti-Aging & Longevity
Somatropin (HGH)- Summary
- Spermidine is a naturally occurring polyamine found in all living cells, with exceptionally high concentrations in wheat germ, aged cheese, and human sperm. It is the most studied autophagy-inducing dietary compound, shown to extend lifespan across multiple species and reduce cardiovascular and cognitive aging.
- Somatropin is recombinant human growth hormone (rhGH), identical in structure to the 191-amino acid pituitary-derived growth hormone. It is FDA-approved for growth hormone deficiency, short stature, and wasting conditions. Off-label, it is widely explored for body composition, anti-aging, and performance enhancement, though significant risks accompany unsupervised use.
- Half-Life
- ~30–60 minutes, but gut bacteria produce it continuously; supplementation raises tissue levels over weeks
- 2-3 hours (subcutaneous); 20-30 minutes (intravenous)
- Admin Route
- Oral
- Subcutaneous, Intramuscular (less common)
- Research
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- Typical Dose
- 1–5 mg
- 0.15-0.3 mg/day (adults); titrated to IGF-1 levels
- Frequency
- Once daily
- Once daily
- Key Benefits
- Induces autophagy — cellular self-cleaning
- Extends lifespan in yeast, flies, worms, and mice
- Reduces cardiovascular aging and arterial stiffness
- Reduces all-cause mortality (human epidemiological data)
- Neuroprotective: reduces amyloid and tau pathology
- Promotes hair growth (anagen phase activation)
- Reduces age-related immune decline
- Improves memory in aging models
- Increases lean muscle mass and reduces body fat (particularly visceral)
- Restores growth hormone deficiency (FDA-approved)
- Improves bone mineral density
- Enhances exercise capacity and recovery
- Supports skin thickness and collagen synthesis
- Improves lipid profile in GHD patients
- Explored for anti-aging and cellular regeneration
- Side Effects
- Generally very well tolerated
- Rare: mild GI discomfort at high doses
- May temporarily reduce some gut bacteria species
- Rare: headache at initiation
- Fluid retention and edema (common, dose-dependent)
- Carpal tunnel syndrome
- Joint and muscle pain
- Insulin resistance and elevated blood glucose
- +3 more
- Stacks With
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