Calcium AKG vs Spermidine
Both are preclinical stories with a striking human number attached, and in both cases the number comes from a study design that cannot carry it.
Calcium AKG
Ca-AKG / Rejuvant
Compresses morbidity in mice and inhibits TOR in worms — but the human '~8 years younger' headline is from a single uncontrolled, industry-linked methylation-clock study, with no RCT on hard outcomes.
Full Calcium AKG evidence reviewSpermidine
Autophagy + mouse-lifespan data and a striking diet-mortality association — but the best randomized human trial (memory) was null.
Full Spermidine evidence reviewSide by side
| Calcium AKG | Spermidine | |
|---|---|---|
| Marketed for | Biological-age reduction, longevity | Autophagy, longevity |
| Evidence grade | Preclinical / minimal | Preclinical / minimal |
| Family | mTOR & other | Senescence & senolytic |
| Key human source | Mouse morbidity, Cell Metab 2020 | Mouse lifespan, Nat Med 2016 |
marks a row where the two differ. Evidence grades come from our evidence matrix, which grades each molecule on the human data for the use it is marketed for.
Our verdict
Neither has a randomized trial showing a hard human outcome, so the honest comparison is between two thin human evidence bases rather than a winner. Ca-AKG compresses morbidity in aging mice and inhibits TOR in worms, but its viral figure of roughly eight years younger comes from an uncontrolled, retrospective, industry-linked analysis of customers using a DNA-methylation clock. Spermidine has mouse lifespan and cardiac data tied directly to autophagy, plus a dietary cohort in which the highest intake tracked with substantially lower all-cause mortality, an association confounded by generally healthier diets. Spermidine has at least faced a proper randomized test, and the 12-month SmartAge trial found no effect on its primary memory endpoint; that null result is more informative than anything Ca-AKG has produced.
Calcium AKG fits if
Ca-AKG appeals to the reader who finds the declining-metabolite rationale compelling and is willing to fund a preclinical bet while disregarding the biological-age headline entirely.
Spermidine fits if
Spermidine suits someone who prefers a candidate that has been through a year-long randomized trial, and who reads its null memory result as a reason to keep expectations low.