Spermidine vs Dihexa
Side-by-side comparison of key properties, dosing, and research.
Anti-Aging & LongevityCognitive Enhancement
SpermidineCognitive Enhancement
Dihexa- 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.
- Dihexa is a potent experimental oligopeptide derived from angiotensin IV that dramatically enhances synaptogenesis. Preclinical research shows cognitive enhancement orders of magnitude more potent than BDNF — it is considered one of the most powerful nootropic compounds in research, but has very limited human safety data.
- Half-Life
- ~30–60 minutes, but gut bacteria produce it continuously; supplementation raises tissue levels over weeks
- Unknown (limited pharmacokinetic data)
- Admin Route
- Oral
- Oral, SubQ, Topical
- Research
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- Typical Dose
- 1–5 mg
- 5–10 mg
- Frequency
- Once daily
- 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
- Dramatically increases synapse formation (potentially 10 million× more potent than BDNF in animal models)
- Enhances memory and learning
- May reverse cognitive decline
- Improves neuroplasticity and executive function
- Long-lasting cognitive benefits from short courses
- Potential therapeutic agent for Alzheimer's
- Side Effects
- Generally very well tolerated
- Rare: mild GI discomfort at high doses
- May temporarily reduce some gut bacteria species
- Rare: headache at initiation
- Headache
- Irritability
- Brain fog during washout period
- Unknown long-term effects (insufficient data)
- Stacks With
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