Real biological signals — mostly mechanistic, biomarker, or animal data — without large human endpoint trials. Access ranges from prescription to supplement counter; quality of evidence and of products varies accordingly.
Rapamycin / sirolimus (mTOR inhibition)
The most consistent life-extension drug in mice
Evidence: The NIA Intervention Testing Program (ITP) repeatedly extended lifespan in genetically heterogeneous mice with rapamycin started even late in life (Miller et al., Aging Cell 2014 and follow-ups) — one of the most replicated mouse findings in geroscience.
Caveats: Human longevity data: none. Chronic dosing carries immune suppression, lipid, and wound-healing risks (it is a transplant immunosuppressant). Off-label 'longevity dosing' exists in private clinics; that is a clinician conversation with real trade-offs, not a supplement decision.
Named a prescription medicine? Decisions on starting, stopping, or combining belong with a qualified clinician.
NAD+ precursors (NR, NMN)
The subscription-supplement poster child
Evidence: Small human trials show NAD+ levels in blood rise reliably (e.g. Martens et al. 2018, which also saw a blood-pressure trend). Mechanistic work on sirtuins and mitochondrial function is extensive.
Caveats: No human trial has shown a clinical endpoint — survival, disease, function — improving. NMN's regulatory status is contested (novel-food battles in the US/UK). This category is sold on mechanism, not outcomes.
Named a prescription medicine? Decisions on starting, stopping, or combining belong with a qualified clinician.
Taurine
A real signal, in mice and monkeys
Evidence: Singh et al. (Science 2023) found taurine supplementation improved healthspan markers and lifespan in mice and monkeys, with taurine levels declining with age across species — a genuinely interesting paper.
Caveats: No human endpoint evidence; the ageing effect has not been demonstrated in people. Human data is limited to small blood-pressure and exercise-metabolism trials. Well tolerated up to 3 g/day per EFSA.
Named a prescription medicine? Decisions on starting, stopping, or combining belong with a qualified clinician.
Omega-3 (EPA/DHA)
The old reliable — with a split verdict
Evidence: REDUCE-IT (icosapent ethyl, prescription EPA) reduced cardiovascular events in high-risk patients on statins. Blood-pressure and triglyceride effects are real and measurable.
Caveats: General-population supplement trials (VITAL, ASCEND) found no reduction in cardiovascular events, and meta-analyses show no all-cause mortality benefit; high doses carry an atrial-fibrillation signal. Food-first still wins for most people.
Named a prescription medicine? Decisions on starting, stopping, or combining belong with a qualified clinician.