Longevity Supplements Ranked by Evidence: What Holds Up and What Is Hype

Search "longevity supplements" and you will find dozens of compounds promising to slow aging. Very few have been tested in randomized human trials, and almost none have been shown to extend human lifespan. That is the honest starting point. The more useful question is narrower: which compounds have human data showing they move a measurable aging-related marker, and how strong is that data?

This guide ranks nine of the most discussed longevity ingredients by the quality of their human evidence — not by mouse lifespan headlines.

How We Ranked the Evidence

We used a simple hierarchy: meta-analyses and multiple randomized controlled trials (RCTs) in humans rank highest, followed by single RCTs, then observational data, then animal and cell studies. We favored research published since 2021. A compound earns a higher tier when human trials show a consistent effect on a relevant marker, not just a plausible mechanism.

Tier 1: Strongest Human Evidence

NMN (Nicotinamide Mononucleotide)

What it is: A direct precursor to NAD+, a coenzyme involved in cellular energy metabolism and DNA repair. NAD+ levels decline with age, which is the core rationale for supplementing precursors. (For background, see our complete guide to NAD+ supplements.)

What the research shows: A 10-week RCT in postmenopausal women found 250 mg/day NMN increased muscle insulin sensitivity compared with placebo (Yoshino et al., 2021). A 60-day multicenter RCT in healthy middle-aged adults tested 300, 600, and 900 mg/day and reported dose-dependent increases in blood NAD+ concentrations, with improvements in six-minute walking distance at the higher doses (Yi et al., 2023). Several smaller trials have confirmed that oral NMN reliably raises blood NAD+ and appears well tolerated.

Evidence verdict: Consistent evidence that NMN raises NAD+ in humans; functional outcomes are early but encouraging.

Urolithin A

What it is: A compound produced by gut bacteria from ellagitannins in pomegranates and walnuts. Many people do not produce meaningful amounts on their own, which makes direct supplementation relevant. It appears to support mitophagy — the recycling of worn-out mitochondria.

What the research shows: In a 4-month RCT in older adults, 1,000 mg/day Urolithin A improved muscle endurance markers and reduced plasma markers associated with mitochondrial dysfunction (Liu et al., 2022). A separate RCT in middle-aged adults found both 500 mg and 1,000 mg/day improved muscle strength and exercise performance measures over 4 months (Singh et al., 2022).

Evidence verdict: Among the best-supported mitochondrial compounds, with RCTs at both 500 mg and 1,000 mg.

Tier 2: Promising but Mixed

Resveratrol

Resveratrol drew enormous attention after early sirtuin research, but human results have been inconsistent. Meta-analyses suggest small effects on some cardiometabolic markers, with high variability between trials and notoriously poor bioavailability (PubMed: resveratrol meta-analyses). It is better understood as a supporting antioxidant than as a standalone longevity agent. More detail in our trans-resveratrol dosing guide.

Glycine

Glycine is an amino acid and a building block of glutathione, the body's primary intracellular antioxidant. Small trials combining glycine with NAC ("GlyNAC") in older adults reported improvements in glutathione levels and markers of oxidative stress (PubMed: GlyNAC trials). Glycine also has independent human data on sleep quality. Trials are small; replication is needed.

Taurine

A widely cited 2023 study found taurine levels decline with age and that supplementation extended healthy lifespan in mice and worms, with improved health markers in middle-aged monkeys (Singh et al., 2023). Human data on longevity-specific outcomes are still limited, though taurine has a long safety record.

Spermidine

Spermidine is a polyamine that appears to support autophagy. Observational data link higher dietary intake with favorable outcomes, but the 12-month SmartAge RCT found no significant memory benefit from spermidine supplementation versus placebo in older adults with subjective cognitive decline (Schwarz et al., 2022). That is an honest null result, and it keeps spermidine in Tier 2.

Tier 3: Mostly Preclinical

Fisetin

Fisetin, a flavonoid in strawberries, showed senolytic activity (clearing senescent cells) and extended lifespan in aged mice. Human RCTs are underway, but published outcome data remain sparse (PubMed: fisetin senolytic research).

Quercetin

Quercetin is best known in aging research in combination with the drug dasatinib as a senolytic. On its own, human data on aging markers are limited, though it is a well-characterized dietary antioxidant.

PQQ (Pyrroloquinoline Quinone)

PQQ appears to support mitochondrial biogenesis in cell and animal studies. A few small human trials have reported modest changes in inflammatory markers and cognitive measures (PubMed: PQQ human trials), but the evidence base is thin.

Summary Table

Ingredient	Primary pathway	Evidence tier
NMN	NAD+ metabolism	Tier 1
Urolithin A	Mitophagy	Tier 1
Resveratrol	Sirtuins / antioxidant	Tier 2
Glycine	Glutathione synthesis	Tier 2
Taurine	Multiple (osmotic, mitochondrial)	Tier 2
Spermidine	Autophagy	Tier 2
Fisetin	Senolytic	Tier 3
Quercetin	Senolytic / antioxidant	Tier 3
PQQ	Mitochondrial biogenesis	Tier 3

Dosing & Practical Considerations

• Match studied doses where possible. NMN trials used 250–900 mg/day; Urolithin A trials used 500–1,000 mg/day. Doses below the studied range have less support.
• Give it time. Most trials ran 8–16 weeks before measuring outcomes. A 90-day window is a reasonable minimum to judge personal response.
• Timing. NAD+ precursors are commonly taken in the morning, aligned with natural circadian NAD+ rhythms; most other compounds here can be taken with food at any time.
• Prioritize the base. Sleep, resistance training, and diet quality have far larger effect sizes on healthy aging than any supplement on this list.

Safety & Interactions

NMN and Urolithin A were well tolerated in the trials above, with adverse event rates similar to placebo. Resveratrol and quercetin may interact with blood thinners and drugs metabolized by CYP enzymes. Spermidine is generally well tolerated at dietary-range doses. Anyone who is pregnant, nursing, managing a medical condition, or taking prescription medication should consult a healthcare provider before starting a longevity stack.

Bottom Line

If you are going to spend money on longevity supplements, NMN and Urolithin A have the most credible human evidence today, with measurable effects on NAD+ levels and mitochondrial and muscle markers. Resveratrol, glycine, taurine, and spermidine are reasonable supporting players with mixed data. Fisetin, quercetin, and PQQ rest mostly on preclinical promise. None of them replace sleep, exercise, and a good diet.

Frequently Asked Questions

Has any supplement been proven to extend human lifespan?

No. Current human trials measure biomarkers and function — NAD+ levels, muscle endurance, oxidative stress — not lifespan.

NAD+ precursors vs. resveratrol: which has better evidence?

NMN has more consistent human data showing it raises NAD+. Resveratrol's human results are mixed and limited by poor bioavailability.

Is Urolithin A the same as eating pomegranates?

Not necessarily. Your gut bacteria must convert pomegranate ellagitannins into Urolithin A, and many people produce little or none. Supplementation delivers it directly.

How long before I notice anything?

Most trials measured changes after 8–16 weeks. Many effects are biochemical and may not be subjectively noticeable.

Can I take these together?

Many people combine compounds that act on different pathways. That approach is reasonable, but few combinations have been tested as a whole, so speak with a healthcare provider if you take medications.

Ready to put the science into practice?

Evoria's Total Longevity combines nine longevity ingredients in one daily stick pack — including NMN at 600 mg (within the 300–900 mg range studied) and Urolithin A at 500 mg (a dose tested in human trials) — to support cellular energy and mitochondrial health. Shop Total Longevity →

References

1. Yoshino M, et al. Nicotinamide mononucleotide increases muscle insulin sensitivity in prediabetic women. Science. 2021. PubMed
2. Yi L, et al. The efficacy and safety of β-nicotinamide mononucleotide (NMN) supplementation in healthy middle-aged adults: a randomized, multicenter, double-blind, placebo-controlled, parallel-group, dose-dependent clinical trial. GeroScience. 2023. PubMed
3. Liu S, et al. Effect of Urolithin A supplementation on muscle endurance and mitochondrial health in older adults: a randomized clinical trial. JAMA Network Open. 2022. PubMed
4. Singh A, et al. Urolithin A improves muscle strength, exercise performance, and biomarkers of mitochondrial health in a randomized trial in middle-aged adults. Cell Reports Medicine. 2022. PubMed
5. Singh P, et al. Taurine deficiency as a driver of aging. Science. 2023. PubMed
6. Schwarz C, et al. Effects of spermidine supplementation on cognition and biomarkers in older adults with subjective cognitive decline: a randomized clinical trial. JAMA Network Open. 2022. PubMed

These statements have not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.