Spermidine
What it is
Naturally occurring polyamine that induces autophagy; epidemiologically linked to lower mortality.
What the evidence says
Spermidine's human RCT evidence is thin and largely negative for hard endpoints. The phase-2b SmartAge trial randomized 100 older adults with subjective cognitive decline to ~0.9 mg/day spermidine (wheat-germ extract) for 12 months and found no improvement in memory versus placebo (adjusted effect -0.03). Authors noted the dose may have been too low. Observational data associate higher dietary spermidine with lower mortality, but causation is unproven and intervention evidence is preliminary.
~1 mg/day used (likely sub-therapeutic); optimal supplemental dose undefined
Educational summary of doses studied — not a recommendation. Talk to a clinician before starting any supplement.
Sources (1)
- Effects of Spermidine Supplementation on Cognition and Biomarkers in Older Adults With Subjective Cognitive Decline: A Randomized Clinical Trial (SmartAge) — JAMA Network Open (PMID: 35616942) (2022)
Educational summary of published research, checked against primary sources and linked inline. Not medical advice; supplements are not FDA-evaluated to treat disease. See our editorial policy.