How We Grade Evidence
Each grade is for a stated outcome, shown on the card, and reflects randomized trials in people. No supplement has been shown in trials to slow human aging itself, so no grade here means that.
A
Strong
Consistent randomized-trial evidence in people for the stated benefit.
B
Moderate
Trials show benefits on intermediate measures, such as blood sugar or blood pressure, or limited benefits on outcomes.
C
Limited or mixed
Mostly animal or laboratory evidence, or small, short or conflicting human trials.
D
Evidence against
Well-designed trials found no benefit for the main promoted use, or found harm.
Rx
Prescription Only
Prescription drugs, described with their approved uses; any use for aging is off-label and unproven.
🔬
No compounds match your search
Try a broader search term or clear the filter.
Why This Database Exists
The problem with longevity supplement marketing
The supplement industry operates on a fundamental information asymmetry: companies know the evidence limitations of their products far better than consumers do. This database is our attempt to close that gap systematically.
🔬
The Animal Data Problem
The history of longevity supplements is littered with compounds that dramatically extended lifespan in worms, flies, or mice — and failed to replicate in humans. Resveratrol is the canonical example: extraordinary animal results, failed human RCTs. Our grading system explicitly penalizes animal-only evidence, regardless of how mechanistically compelling it is. A compound cannot exceed Grade C without human trial data.
💰
Industry-Funded Research
The majority of human supplement trials are funded by manufacturers. This doesn't make findings wrong, but it does mean they require independent replication before being treated as definitive. Studies funded by manufacturers are more likely to report favorable results, so we require independent replication before giving a high grade.
📊
Surrogate vs. Hard Endpoints
Many supplements demonstrate positive effects on biomarkers — blood NAD+ levels, inflammatory markers, glucose — without demonstrating actual mortality or morbidity benefit. Raising NAD+ is not the same as extending lifespan. Reducing CRP is not the same as preventing a heart attack. We distinguish carefully between surrogate endpoint evidence (what most supplement trials measure) and hard endpoint evidence (what actually matters for longevity).
⏱
The Duration Problem
Many supplement trials last only weeks or months, while effects on longevity would take decades to measure directly. This creates a fundamental evidence ceiling for all longevity supplements: we cannot yet run the trials that would definitively prove or disprove longevity effects. The best available proxy is the combination of mechanistic plausibility, validated biomarker effects in humans, and (where available) population data on dietary intake patterns and mortality outcomes.
Understanding Grade A: what strong evidence means
Grade A means consistent randomized-trial evidence in people for a stated benefit. Only one compound here meets that bar: creatine, which improves lean mass and muscle function in older adults when combined with resistance training.
Four compounds previously graded A here were regraded in October 2026. In the large VITAL and ASCEND trials, fish oil did not prevent heart attacks, strokes or cancer, although a prescription form reduced cardiovascular events in high-risk patients already on statins. In VITAL, vitamin D did not reduce cancer or cardiovascular events. Adding niacin to statins did not prevent cardiovascular events in AIM-HIGH or HPS2-THRIVE. And the best trial evidence for magnesium is a small reduction in blood pressure.
A grade is not a recommendation to take anything. Discuss supplements with your clinician, especially if you take prescription medicines.