Compare
Side by side.
| Spermidine | Metformin | |
|---|---|---|
| Evidence | GRADE D | GRADE B |
| Category | other | metabolic |
| Status | Supplement | Rx |
| Typical cost | $30–$70 / mo | $5–$20 / mo |
| Mechanism | Promotes autophagy, the cell's recycling program, similar in direction to fasting. | Lowers glucose production by the liver and improves insulin sensitivity. It mildly affects mitochondrial energy signaling (AMPK), which may mimic some effects of caloric restriction. |
| Human evidence | Lifespan extension in yeast, worms, flies and mice. Observational human data link higher intake to lower mortality. A small trial on memory showed limited effect. | Observational data suggest diabetics on metformin may have outcomes comparable to non-diabetics. The TAME trial is designed to test aging outcomes but has not reported. Some data suggest it can blunt exercise adaptations in older adults. |
| Side effects | Generally well tolerated | GI upset, diarrhea · Vitamin B12 deficiency with long use · Rare lactic acidosis (kidney impairment) |
Not medical advice — talk to a licensed clinician. Content is educational, reflects published literature, and is not a recommendation to start, stop or change any treatment.