Longevity Supplements With Null Trials: Evidence Ledger
Longevity supplements where the best human trials found no benefit: the claim, the strongest trial or review, the result and a grade for each.
Researched from published studies and manufacturer specifications, checked .
We have not tested products ourselves. How we researchQuick verdict
For several popular longevity supplements, the strongest human trials we read did not meet their main outcomes: antioxidant vitamins, fish oil and vitamin D in large prevention trials, resveratrol, spermidine, and NMN or NR for muscle in older adults; urolithin A is mixed. Antioxidant supplements were linked to slightly higher mortality in the low-risk-of-bias trials of a Cochrane review. A trial that misses its main outcome is not proof of harm or of uselessness in every group.
Talk to your doctor first. This is general information, not medical advice. Supplements and devices can interact with medicines and health conditions. We quote study protocols for context and do not recommend doses.
The short answer: for these popular supplements, the best human trials we read did not show the benefit the marketing implies. Antioxidant supplements did not lower mortality in a Cochrane review of 78 trials, and in the 56 lowest-risk-of-bias trials mortality was slightly higher (relative risk 1.04, 95% CI 1.01 to 1.07). Fish oil and vitamin D in the large VITAL trial, resveratrol, spermidine and NMN or NR also missed their main outcomes, and urolithin A was mixed. A trial that misses its main outcome did not show a benefit; that is not proof of harm, and it does not cover every group. Talk to your doctor before starting or stopping anything.
The ledger
Grades follow the rubric and describe how strong the evidence is that the supplement delivers the claimed benefit. “Weak” means a null or contradicted result in the best evidence.
| Compound | Popular claim | Strongest human evidence | Result | Grade |
|---|---|---|---|---|
| Antioxidant vitamins (vitamin A, C, E, beta-carotene, selenium) | Slow aging, prevent disease | Cochrane review 2012: 78 RCTs, 296,707 participants | No significant effect on mortality overall in the random-effects model (RR 1.02, 95% CI 0.98 to 1.05; the fixed-effect model gave 1.03, 1.01 to 1.05); in 56 low-risk-of-bias trials, RR 1.04 (1.01 to 1.07); in those trials beta-carotene RR 1.05 and vitamin E RR 1.03 (1.00 to 1.05) were significantly higher, while vitamin A, vitamin C and selenium were not. Trials included healthy and diseased participants | Weak; possible harm for beta-carotene and vitamin E |
| Fish oil (omega-3) | Prevent heart attacks and strokes | VITAL: 25,871 adults in primary prevention, dose used in VITAL 1 g/day of marine n-3; STRENGTH: 13,078 high-risk statin-treated patients, dose used in STRENGTH 4 g/day of a carboxylic-acid EPA and DHA formulation versus corn oil (a prescription-type product, not typical shop fish oil) | VITAL major cardiovascular events HR 0.92 (0.80 to 1.06, not significant); a secondary endpoint, total myocardial infarction, was lower (HR 0.72, 0.59 to 0.90) and is hypothesis-generating. STRENGTH HR 0.99 (0.90 to 1.09). Prescription EPA (REDUCE-IT) is the exception in high-risk patients, covered on the omega-3 page | Weak for primary prevention with fish oil; see omega-3 page |
| Vitamin D, general adult population | Prevent cancer and heart disease; live longer | VITAL vitamin D: 25,871 adults, dose used in VITAL 2,000 IU/day, median 5.3 years; BMJ 2019 meta-analysis of 52 RCTs, 75,454 people | VITAL cancer HR 0.96 (0.88 to 1.06) and cardiovascular events HR 0.97 (0.85 to 1.12), neither significant; death from cancer HR 0.83 (0.67 to 1.02), not significant. Meta-analysis: all-cause mortality RR 0.98 (0.95 to 1.02), but cancer death was lower (RR 0.84, 0.74 to 0.95), so it is not a clean null | Weak for the main outcomes, with a cancer-death signal still debated; see vitamin D page |
| Resveratrol | Mimics caloric restriction, longer life | Semba 2014 (783 adults 65+, observational, dietary resveratrol, not a supplement trial); 11-study meta-analysis of randomised trials, 388 people | No association of urinary resveratrol metabolites with mortality (lowest versus highest quartile HR 0.80, 0.54 to 1.17); meta-analysis: glucose control improved in people with diabetes, no effect in people without. No trial of resveratrol and lifespan | Weak; see resveratrol page |
| NMN and NR | Raise NAD+, restore strength | 2025 meta-analysis for muscle in adults over 60 | No significant effect on muscle mass, grip strength or gait speed; blood NAD+ rises | Weak to emerging; see NMN page |
| Spermidine | Autophagy, memory, longer life | SmartAge RCT: 100 older adults, 12 months, 0.9 mg/day | No significant change in memory (between-group difference -0.03, 95% CI -0.11 to 0.05) or in secondary outcomes; exploratory analyses hinted at benefits for verbal memory and inflammation. Authors have financial ties to a spermidine maker. The mortality link comes from an observational cohort | Weak; see spermidine page |
| Taurine | Declining taurine drives aging | Science 2025 (NIA) and an Aging Cell 2025 study | Circulating taurine increased or stayed unchanged with age in three human cohorts, so the premise that it falls with age was not supported. These studies measured blood levels and did not test supplements; a 2026 meta-analysis of taurine supplementation reported cardiometabolic risk markers, not outcomes | Weak; see taurine page |
| Urolithin A | Mitochondrial renewal, strength | JAMA Netw Open 2022: 66 older adults | Mixed: the primary endpoints (6-minute walk distance, muscle ATP) were not significantly improved, but muscle endurance at 2 months and some blood markers favoured urolithin A, and the authors concluded it may counteract muscle decline pending confirmation. Several authors are employees, founders or shareholders of Amazentis, which makes the Mitopure product | Emerging; see urolithin A page |
Trial and review figures in this table were re-read from PubMed abstract records on 2 Oct 2026 (the Cochrane review, both VITAL papers, STRENGTH, the BMJ meta-analysis, Semba, the resveratrol meta-analysis, SmartAge, the urolithin A trial and the Science taurine paper); NMN and NR, and the 2026 taurine meta-analysis, rest on supplement pages already audited on this site.
What this does not say
- Not “proven useless”. Trials ask specific questions in specific groups; products named elsewhere on this site are discussed on their own pages, and every finding here is the cited trial’s or review’s. REDUCE-IT’s prescription EPA helped high-risk patients on statins; CoQ10 has support in chronic heart failure, per our CoQ10 page; creatine has the best support for muscle in older adults who lift, per our creatine page.
- Not a reason to stop prescribed medicines. Do not stop anything a clinician prescribed without asking them.
- Deficiency is different. A deficient person is a different case from a healthy adult; a blood test, not a supplement, tells you which you are.
What a null result costs you
At the dose used in the trials, a month of spermidine, urolithin A and NR costs tens to hundreds of dollars on the prices we read; see the cost per study dose table and the graded supplement ladder for where each sits.
Method note
Researched from PubMed abstract records (read 2 Oct 2026) and supplement pages already audited on this site; findings are the cited authors’ and no product is rated by us; grades are our judgement using the published rubric. We did not test any product. General information, not medical advice.
Common questions
Do longevity supplements actually work?
For most we found no human trial showing longer life or fewer deaths. The ledger below lists, for each, the strongest trial or review we read and what it found. A few have narrower support in specific groups, such as prescription EPA in high-risk heart patients or CoQ10 in heart failure.
Which supplements raise death risk?
A 2012 Cochrane review of 78 randomised trials (296,707 participants) found antioxidant supplements had no significant effect on mortality overall (RR 1.02, 95% CI 0.98 to 1.05), but in the 56 low-risk-of-bias trials mortality was slightly higher (RR 1.04, 95% CI 1.01 to 1.07). In those low-risk-of-bias trials, beta-carotene and vitamin E were associated with higher mortality, while vitamin A, vitamin C and selenium were not significantly associated with it. The trials included both healthy people and people with stable disease.
Is resveratrol worth it?
We found no human trial showing longer life. In 783 older Italian adults, an observational study of resveratrol from ordinary diet found no link between urinary resveratrol metabolites and mortality (lowest versus highest quartile HR 0.80, 95% CI 0.54 to 1.17; this does not test supplements), and a meta-analysis of 11 randomised trials (388 people) found glucose benefits in people with diabetes but not in people without it.
Sources
- Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases (Cochrane 2012) checked 2 Oct 2026
- VITAL, marine n-3 fatty acids and prevention of cardiovascular disease and cancer (NEJM 2019) checked 2 Oct 2026
- STRENGTH, high-dose omega-3 fatty acids in statin-treated patients (JAMA 2020) checked 2 Oct 2026
- VITAL, vitamin D and cancer and cardiovascular disease (NEJM 2019) checked 2 Oct 2026
- Vitamin D supplementation and mortality, systematic review and meta-analysis of 52 RCTs (BMJ 2019) checked 2 Oct 2026
- Urinary resveratrol metabolites and mortality in older adults (Semba, JAMA Intern Med 2014) checked 2 Oct 2026
- Resveratrol and glucose control, meta-analysis of 11 RCTs (Am J Clin Nutr 2014) checked 2 Oct 2026
- NMN and NR for muscle mass and function, systematic review and meta-analysis (J Cachexia Sarcopenia Muscle 2025) checked 2 Oct 2026
- Spermidine supplementation in subjective cognitive decline, SmartAge RCT (JAMA Netw Open 2022) checked 2 Oct 2026
- Is taurine an aging biomarker? (Science 2025) checked 2 Oct 2026
- Urolithin A and muscle endurance in older adults, RCT (JAMA Netw Open 2022) checked 2 Oct 2026
- Longevity Intel cost per study dose dataset (prices checked 28 to 29 Sept 2026) checked 2 Oct 2026
Update log
- New page: an evidence ledger pulling together null or mixed results already read in our supplement pages, plus the Cochrane antioxidant review, with the Cochrane figures read from PubMed on 2 Oct 2026.
Data and comparisons
- CoQ10 evidence record
Essential for mitochondrial electron transport chain
- Creatine evidence record
The most evidence-backed performance supplement
- NMN evidence record
A direct NAD+ precursor that restores declining NAD+ levels with age
- NR evidence record
An alternative NAD+ precursor with more human trial data than NMN
- Cardio Modalities Compared: Run vs bike vs row vs swim
Stack modalities
- Creatine vs HMB: Best anti-sarcopenia supplement?
Creatine
Related reading
Creatine for Longevity: Evidence, Forms, Cost
Creatine monohydrate from meta-analyses: muscle, memory and bone in older adults, kidney and hair concerns, and monthly cost at a trial dose.
Magnesium Supplements: Evidence by Form, and Cost
Magnesium from trials and meta-analyses: blood pressure, sleep in older adults, the L-threonate memory trial, and monthly cost at the dose a review used.
Vitamin D3 + K2: What the Evidence Supports, and Cost
Vitamin D3 and K2 (MK-7) from trials and guidelines: who benefits, what large trials found, safety limits, and monthly cost at the dose used in a trial.
Curcumin: Arthritis Trials, Not Longevity
Curcumin: a meta-analysis of 29 RCTs found improved pain and inflammation in arthritis, with low-quality trials; no evidence it extends life.
Spermidine: Observational Link, Null Trial
Spermidine's lower-mortality link is from a food-questionnaire cohort; the best supplement RCT (SmartAge, 100 adults, 12 months) found no memory benefit.