In brief: Spermidine supplements usually contain spermidine-rich extracts such as wheat-germ extract. Biological plausibility exists, but human clinical evidence remains limited.
What did the main long-term trial show?
| Feature | Study |
|---|---|
| Participants | 100 older adults with subjective cognitive decline |
| Duration | 12 months |
| Spermidine | 0.9 mg/day |
| Primary outcome | No significant memory benefit versus placebo |
The randomised JAMA Network Open trial found no significant improvement in the primary memory endpoint or major secondary outcomes after 12 months.[1]
Anti-ageing claims?
Animal and cell studies on autophagy do not prove that spermidine supplements slow human ageing or extend life.
Safety and uncertainties
Adverse events were balanced in the trial, but long-term data at higher doses and in special populations remain limited.
FAQ
Does spermidine reliably improve memory?
No.
Does it slow ageing?
Not proven in humans.
Is 0.9 mg the optimal dose?
No. It was the dose used in one trial.
Are wheat-germ extracts automatically better?
No.
Conclusion
Spermidine supplements are scientifically interesting but are not proven anti-ageing or memory treatments.
