Hexarelin vs Spermidine
Side-by-side comparison of key properties, dosing, and research.
Growth Hormone Peptides
HexarelinAnti-Aging & LongevityCognitive Enhancement
Spermidine- Summary
- Hexarelin is a potent synthetic GHRP and the strongest GH secretagogue in its class per unit dose. It also exhibits unique cardioprotective properties through direct binding to cardiac CD36 receptors, independent of GH release. Its potency is balanced by a tendency to desensitize GH release with prolonged use, making cycling important.
- 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.
- Half-Life
- ~70 minutes
- ~30–60 minutes, but gut bacteria produce it continuously; supplementation raises tissue levels over weeks
- Admin Route
- SubQ
- Oral
- Research
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- Typical Dose
- 100–200 mcg
- 1–5 mg
- Frequency
- 2–3 times daily
- Once daily
- Key Benefits
- Strongest GH pulse per mcg among GHRPs
- Unique direct cardioprotective effects via CD36
- Increased IGF-1 and muscle anabolism
- Accelerated recovery from training
- Bone density support
- Anti-aging via GH axis
- Potential cardiac rehabilitation 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
- Side Effects
- Water retention
- Elevated cortisol
- Elevated prolactin (more pronounced than other GHRPs)
- Receptor desensitization with continuous use
- +1 more
- Generally very well tolerated
- Rare: mild GI discomfort at high doses
- May temporarily reduce some gut bacteria species
- Rare: headache at initiation
- Stacks With
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