Longevity
Longevity supplements sell a claim that's nearly impossible to test directly in humans — nobody runs a decades-long randomized trial measuring lifespan. What actually exists behind most of these (NAD precursors, resveratrol, fisetin, spermidine, and similar) is animal research and mechanistic work on aging pathways, plus a smaller number of human trials on surrogate markers like inflammation. Read the grade here as evidence-of-mechanism, not evidence-of-more-years.
8 products · sorted by evidence grade
Common questions
Which longevity supplement has the best evidence?
Two products in this category carry a Grade B rating; the other four are Grade C. Urolithin A (Mitopure) has the strongest muscle evidence: two placebo-controlled RCTs (88 middle-aged adults and 66 adults aged 65-90, each over 4 months) show roughly 10-12% leg-strength gains and improved muscle endurance, though every human RCT to date was funded by the manufacturer, Amazentis. Quercetin is also Grade B, but for a different benefit — meta-analyses of human RCTs show it modestly lowers inflammatory markers like CRP (its senolytic "zombie-cell" claim is only Grade C). The remaining four — NAD+ precursors (NMN/NR), spermidine, fisetin, and resveratrol — are all Grade C: interesting mechanisms, but no confirmed clinical benefit in people. So the strongest trial-backed cases are for muscle strength and endurance (urolithin A) and lower inflammation (quercetin), not for "living longer."
Do any of these actually extend lifespan in humans?
No, and that is why four of the six are graded C. Resveratrol is the clearest cautionary tale: a 9-year cohort of 783 older adults (InCHIANTI) found urinary resveratrol levels had no link to mortality, cardiovascular disease, or cancer. Fisetin's striking lifespan results are in mice only; NAD+ precursors reliably raise NAD+ but haven't moved hard clinical outcomes; and spermidine's larger SmartAge RCT (100 adults, 12 months) missed its primary memory endpoint. The two Grade B products don't extend lifespan either — their trial-backed benefits are muscle strength and endurance (urolithin A) and reduced inflammatory markers (quercetin), not longevity. No supplement here has human evidence for living longer.
When the evidence changes, we’ll tell you.
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Medical disclaimer. The information on this site is provided for educational purposes only and is not intended as medical advice. It does not constitute a diagnosis, treatment plan, or recommendation for any specific health condition. Always consult a qualified healthcare professional before making changes to your supplement regimen, diet, or lifestyle — especially if you are pregnant, nursing, taking medications, or managing a medical condition.
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