Best longevity supplements UK: what the evidence actually shows

Start with the uncomfortable summary

No supplement has been shown to extend human lifespan. Not one. The strongest candidates have evidence for narrower things: raising a blood marker, adding to strength-training gains, or improving a risk factor. Those narrower claims are worth understanding — and worth distinguishing ruthlessly from the lifespan claims used to sell them.

Where large randomised trials have directly tested supplements against hard outcomes in healthy people, the results have mostly been null. Vitamin D did not reduce mortality in over 21,000 older adults in the D-Health trial. A gram a day of fish oil prevented neither cardiovascular disease nor cancer in the 25,000-person VITAL trial.

Vitamin D evidence →Omega-3 evidence →

Creatine: the quiet overperformer

Creatine is not marketed as a longevity supplement, which is perhaps why its evidence is comparatively honest. In older adults, trials consistently suggest it adds a modest amount to the strength gains of resistance training. Muscle strength matters for ageing in a way most supplement targets do not: it predicts independence. What creatine does not have is any human lifespan evidence — and unlike most of this list, its sellers rarely pretend otherwise.

Creatine evidence →

The NAD+ family: NMN and nicotinamide riboside

NMN and NR reliably do one thing in humans: raise blood NAD+ levels. That is a laboratory measurement, not a health outcome, and the distinction is the entire business model. Trials measuring actual health endpoints have been small, short and inconsistent. If raising NAD+ translated straightforwardly into feeling or ageing better, a decade of human trials should have shown it clearly by now. It has not.

NMN evidence →Nicotinamide riboside evidence →

Spermidine and taurine: two cautionary tales in progress

Spermidine illustrates the gap between association and intervention: people who eat spermidine-rich diets die less often in cohort studies, but the flagship randomised trial of spermidine supplements found no memory benefit in older adults. Taurine illustrates something rarer — evidence actively evolving. A 2023 Science paper reported mouse lifespan extension and an age-related decline in humans; a 2025 human analysis then reported evidence against that decline existing at all. Watch this one rather than buy it.

Spermidine evidence →Taurine evidence →

How to read any supplement claim

Three questions cut through most marketing. Was the outcome measured in humans? Was it a health outcome, or a blood marker standing in for one? And has the result been replicated by a group that does not profit from it? Most longevity supplement claims fail the first question, nearly all fail at least one.

Our full methodology →