About Spermidine
Polyamine compound studied for autophagy and cellular aging. Strong mechanism in cell and animal work, but the largest human RCT (SmartAge, n=100, 12 months, 0.9 mg/day) was null on its primary cognitive endpoint. A 28-day 40 mg/day pharmacokinetic trial in older men showed minimal effect on circulating polyamines and no blood-pressure change. One open-label dementia signal and one industry-affiliated hair-follicle trial round out the clinical base; no meta-analyses exist. Pregnancy and active cancer are caution flags — polyamine biosynthesis is also a tumor-growth pathway. No established RDA or UL.
What Spermidine supports
- Activates autophagy — the cellular-cleanup mechanism — in cell and animal models
- Higher dietary spermidine intake tracks with lower mortality in observational human cohorts
- Studied for memory in older adults — the best-designed RCT was null
How much Spermidine to take
Clinical studies typically use 1–6 mg of Spermidine. Wheat-germ-extract trials use 0.9–3.3 mg/day. Synthetic spermidine 3HCl has been tested up to 40 mg/day with minimal rise in circulating spermidine — no efficacy signal at high dose. Range capped at 6 mg to reflect the trial-supported window plus a small buffer; higher-label products (10–15 mg) get no additional credit because there's no clinical data above ~3 mg.
- Effective range
- 1–6 mg
Clinical evidence
Limited clinical evidence. Mechanism is strong; the human clinical-trial base is thin and the largest RCT to date was null. Treat as exploratory, not established.
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