The Longevity Protocol

The longevity supplement space is crowded with hype and compounds that work in mice but have never been tested rigorously in humans. This protocol sorts the field by evidence tier — because the difference between “compelling rodent data” and “replicated human RCTsRCT (randomized controlled trial) A study that randomly sorts participants into a treatment group or a comparison group. Randomizing this way is the most reliable method for telling whether a treatment actually works, rather than just appearing to.” matters clinically. For each supplement, we cover what the actual human evidence shows, the supported dose, and the PharmD-level safety considerations.

A note on scope: This protocol is for otherwise healthy adults seeking to extend healthspanhealthspan The years of your life spent in good health — as opposed to lifespan, which is just total years lived. — years of life lived in good health. It is not a treatment protocol for any specific disease.

A note on the evidence ratings: Each rating reflects the strength of the human evidence for that supplement doing the job this protocol asks of it — not the compound in general. The same supplement can rate differently in another protocol with a different goal.

The Longevity Framework: What Are We Actually Targeting?

Before the supplements, it helps to know what “longevity” means mechanistically. The major hallmarks of aging that supplements can meaningfully influence include:

• NAD+NAD+ (nicotinamide adenine dinucleotide) A molecule every cell needs to make energy and repair DNA. Levels decline with age. decline — a key cellular energy molecule drops about 50% between ages 40 and 60, weakening mitochondriamitochondrial Relating to mitochondria, the structures inside cells that produce energy. and DNA repair
• Declining mitophagymitophagy The cell’s process for clearing out and recycling worn-out mitochondria (its energy factories). It slows with age. — cells get slower at clearing worn-out mitochondria, so damaged ones pile up
• Weaker antioxidant defenses (NRF2NRF2 A master switch inside cells that turns on the body’s own antioxidant and detox defenses. suppression) — the body’s built-in antioxidant system becomes less responsive
• Chronic low-grade inflammation (“inflammaginginflammaging The slow, low-grade inflammation that builds up with age and speeds up most age-related disease.”) — constant, smoldering inflammation that speeds up most age-related disease
• mTORmTOR A cellular control switch that balances growth against cleanup and recycling. Tipped too far toward “growth” with age, it’s thought to accelerate aging./autophagyautophagy The cell’s recycling process that clears out and reuses damaged components. imbalance — the balance between “build” and “clean house” inside cells tips the wrong way with age
• Telomeretelomere The protective cap on the end of a chromosome that shortens each time a cell divides. shortening and DNA damage — genetic wear-and-tear that compounds over time

Each supplement below targets one or more of these pathways. Evidence is graded Strong (replicated human RCTs or large observational studies), Moderate (limited human RCTs or strong mechanistic + epidemiological data), or Emerging (compelling preclinical data, early human trials).

Tier 1: Foundational — Strong Human Evidence

These are the supplements every longevity-focused adult should consider first: the most mature evidence base, well-established safety, and the most favorable cost-to-benefit.

Omega-3 Fatty Acids (EPA + DHA) Moderate–Strong

Omega-3s belong in Tier 1, but for narrower reasons than the label on the bottle claims — and the full evidence review is worth reading before you start.

Be clear about what failed: two large randomized trials of the standard 1 g/day capsule — one in 25,871 general-population adults, one in over 15,000 people with diabetes — found no reduction in cardiovascular events. Pooled meta-analyses across many smaller trials do show modest reductions in cardiac death and myocardial infarction, and one large trial of 4 g/day prescription EPAEPA (eicosapentaenoic acid) A long-chain omega-3 fatty acid found in fatty fish and fish oil, best studied for lowering blood triglycerides and reducing inflammation. cut events by 25%, but a near-identical trial using EPA plus DHADHA (docosahexaenoic acid) A long-chain omega-3 fatty acid that is the primary structural fat in the brain and retina. Found in fatty fish and algae-based supplements. found nothing at all. “Fish oil prevents heart attacks” is not a settled claim.

What holds up is narrower and still worth having: reliable, dose-dependent triglyceridetriglycerides The main form of fat carried in the blood and stored in fat tissue. High levels travel with insulin resistance and cardiovascular risk, and they respond strongly to diet, alcohol, and omega-3 dose. lowering, and a 2025 analysis of the DO-HEALTH trial in which 1 g/day modestly slowed multiple epigeneticepigenetic aging Estimating your biological age from chemical “tags” on your DNA, rather than from your birth date. So-called epigenetic clocks measure it. aging clocks over three years — one of the first demonstrations of a supplement moving a biological-age measure in humans. Mechanistically, EPA and DHA become “specialized pro-resolving mediators” that actively switch inflammation off rather than just suppressing it.

Dose: 1–2 g combined EPA + DHA daily, with food — the dose used in DO-HEALTH, and enough for the anti-inflammatory case. Aim for a high EPA:DHA ratio (at least 2:1), and use marine EPA/DHA rather than plant ALA (poor conversion). The 3–4 g range is a clinical decision for elevated triglycerides or established cardiovascular disease, not a default: the atrial fibrillationatrial fibrillation An irregular, often rapid heart rhythm originating in the upper chambers of the heart. It raises the risk of stroke and is a common reason for blood-thinning medication. signal below appears dose-related.

Form & quality: Triglyceride (rTG) form absorbs modestly better than ethyl ester. OTC quality varies enormously — look for IFOS-certified products, refrigerate, and check the expiration date.

Safety: A meta-analysis of seven cardiovascular outcome trials found omega-3 supplementation raised the risk of atrial fibrillation by about 25% in relative terms, with the signal appearing dose-related — small in absolute terms, but a genuine reason not to megadose by default. Above 3 g/day, omega-3s may also potentiate anticoagulants (warfarin, apixaban, rivaroxaban). Discuss with your pharmacist if you’re on a blood thinner or have a history of arrhythmia.

Vitamin D3 + K2 Strong

Vitamin D is better understood as a hormone than a vitamin — it modulates over 1,000 gene-expression pathways across immune, inflammatory, muscle, and bone function. Deficiency is endemic (40%+ of U.S. adults) and associated with all-cause mortality — though much of that association runs the other way, since illness, obesity, and being housebound all lower vitamin D. The largest randomized test, VITAL (2,000 IU/day in 25,871 adults over five years), found no reduction in cancer incidence or major cardiovascular events; a reduced cancer-death signal appeared only in secondary analyses. The defensible case is correcting real deficiency, not pushing an adequate level higher. K2 (as MK-7) is the useful partner: it directs the extra calcium D3 absorbs into bone and away from artery walls.

Dose: 1,000–2,000 IU D3 daily covers most adults — the RDARDA (recommended dietary allowance) The daily intake of a nutrient judged sufficient to meet the needs of about 97.5% of healthy people. It is a population target, not a personal optimum. is 600 IU (800 over age 70), and no trial has shown added benefit from pushing an adequate level higher. Larger doses belong to lab-confirmed deficiency, corrected under clinician supervision rather than taken indefinitely. Pair with 100–200 mcg K2 as MK-7.

Testing: Worth checking if you have a reason to be low — malabsorption, bariatric surgery, chronic kidney or liver disease, osteoporosis, glucocorticoidsglucocorticoid A class of steroid anti-inflammatory drugs, such as prednisone. Long-term use thins bone and interferes with vitamin D and calcium handling., obesity, or very limited sun. The Institute of Medicine puts sufficiency at 20 ng/mL, and 20–30 covers bone health in nearly everyone; the 40–60 “optimal” band widely quoted online has never been validated against outcomes, and in 2024 the Endocrine Society stepped back from endorsing a universal target at all. Monitor if you are taking high doses for an extended period (toxicity risk begins above 150 ng/mL).

Creatine Monohydrate Strong

Creatine appears in two PrecisionOptimize protocols — in the GLP‑1GLP‑1 (glucagon-like peptide-1) A gut hormone released after eating that boosts insulin, slows the stomach, and signals fullness. Drugs like semaglutide mimic it. Support Protocol for muscle preservation, and here, because its evidence has expanded from exercise performance into cognitive aging and healthspan. Muscle mass is one of the strongest independent predictors of longevity, and creatine is the most-studied supplement for preserving lean masslean mass Body weight that isn’t fat — mostly muscle, bone, and water. across the lifespan. For the brain, a 2023 meta-analysis found it improved memory in healthy adults, with the largest effect in those over 66 — creatine acts as a fast-access energy reserve for demanding mental tasks as mitochondria become less efficient with age.

Dose: 3–5 g/day for general use; 5–10 g/day for older adults (>50) or those prioritizing cognitive protection. No loading phase needed.

Form: Creatine monohydrate only — no evidence supports “advanced” forms. Expect a harmless, expected rise in serum creatinine.

Magnesium Glycinate Strong

Magnesium is a cofactor in over 300 enzymatic reactions, including ATPATP (adenosine triphosphate) The molecule cells use as their direct energy currency. Nearly everything the body does — muscle contractions, brain activity, cellular repair — runs on ATP. synthesis, DNA repair, and protein synthesis — and it plays a direct role in DNA-damage repair and telomere maintenance, with low levels linked to accelerated genomic instability. Deficiency is common (50%+ of Americans suboptimal). Glycinate also improves sleep quality, an independent healthspan driver.

Dose: 200–400 mg elemental magnesium glycinate at night — high bioavailabilitybioavailability How much of a dose actually reaches your bloodstream in active form — often low for drugs taken by mouth., minimal GI side effects (unlike oxide), calming secondary effect.

Tier 2: Emerging — Compelling Human Data, Still Accumulating

These have meaningful human trial evidence but fewer replicated RCTs than Tier 1. The mechanistic rationale is strong, the early data is promising, and the risk-benefit is favorable enough to include — with appropriate caveats.

NMN (Nicotinamide Mononucleotide) Moderate

NAD+ is arguably the most-discussed molecule in longevity science. It declines ~50% between ages 40 and 60, impairing mitochondrial function, DNA repair via PARP enzymes, and sirtuinsirtuin A family of proteins — switched on partly by NAD+ — involved in DNA repair and aging. activity. NMNNMN (nicotinamide mononucleotide) A supplement the body converts into NAD+, marketed for healthy aging. is a direct precursor.

What the human data shows: NMN consistently and meaningfully raises blood NAD+ — this is well-replicated. A 2022 RCT found 300, 600, or 900 mg/day over 60 days significantly elevated NAD+, with optimal effects at 600 mg/day; a separate RCT found 250 mg/day for 12 weeks improved walking speed and sleep in older adults.

The honest caveat: raising NAD+ does not automatically translate to longevity benefits in humans. A 2025 meta-analysis of 10 RCTs found no significant benefit for muscle mass or physical function in older adults. The rodent-to-human gap is real, and hard-endpoint outcome trials don’t yet exist.

Dose: 300–600 mg daily, in the morning (NAD+ is involved in circadian regulation).

NMN vs. NRNR (nicotinamide riboside) Another supplement precursor the body converts into NAD+.: Both raise NAD+. A 2025 head-to-head found NMN produced the most consistent elevation at equivalent doses, though the practical clinical difference is likely small.

Safety note: Generally well-tolerated. A theoretical concern about NAD+ supplementation and cancer-cell growth remains under investigation — worth monitoring if you have a personal or family cancer history.

Urolithin A Moderate–Strong

Urolithin A is the most clinically validated mitophagy-inducing compound available as a supplement — and mitophagy (selective recycling of damaged mitochondria) declines with age. Unusually for this category, it has replicated human RCTs with functional endpoints: a 2022 trial in middle-aged adults found 1,000 mg/day Mitopure® (the proprietary form) for 4 months significantly improved muscle strength (~12%), aerobic endurance, and mitochondrial biomarkers versus placebo; a 2025 study showed it expands naive CD8+ T cells, a marker of immune aging. You can’t reliably get it from food — only 30–40% of people have the gut bacteria to convert dietary ellagitannins (pomegranate, walnuts, berries) into meaningful amounts.

Dose: 500–1,000 mg daily, with food. Trials used Mitopure®; generic “urolithin A” products vary in purity and bioavailability.

Sulforaphane Moderate

Sulforaphane is one of the best-characterized dietary activators of NRF2 — the master switch that turns on the body’s own antioxidant and detox systems (glutathione, thioredoxin, and hundreds more). NRF2 activity falls with age, letting oxidative damage accumulate; ramping up endogenous antioxidant production is a more compelling approach than swallowing antioxidants like vitamin C or E, which have largely failed in longevity trials. Human evidence includes improved pollutant detoxification, fasting glucose and insulin sensitivity, and liver enzymes in fatty liver — though no long-term longevity RCTs exist.

The catch: sulforaphane is unstable, and most products fail to deliver a meaningful dose. The key is active myrosinase, the enzyme that converts glucoraphanin (the broccoli-sprout precursor) into active sulforaphane — often destroyed by heat processing.

Dose: 10–40 mg sulforaphane daily. Choose products that specify active sulforaphane content (not just glucoraphanin) and contain active myrosinase, or add mustard seed powder. Growing broccoli sprouts (30–60 g provides clinical-trial doses) is the most reliable, cost-effective source.

Spermidine Moderate

Spermidine is a naturally occurring polyaminepolyamine A small molecule (spermidine is one) involved in cell growth and the cell’s recycling process. that switches on autophagy — the cell’s broader recycling of damaged proteins and parts — by blocking the enzyme EP300. Where urolithin A targets mitophagy specifically, spermidine triggers general autophagy. Dietary sources (aged cheese, wheat germ, mushrooms, legumes) decline with age. Higher dietary spermidine is associated with reduced all-cause mortality, cardiovascular disease, and cancer in large population studies, and a 2018 RCT found it improved associative memory in older adults with subjective cognitive decline. The Danish POLYCAD RCT (24 mg/day in elderly patients with coronary artery disease) will be the most rigorous trial to date, with results expected in the next 12–18 months.

Dose: 1–10 mg daily for standard supplements; higher-dose formulations (up to 24 mg, matching POLYCAD) sit at the edge of current evidence. This is a long-game supplement — effects build with duration, not days.

Tier 3: Worth Knowing — Mechanistically Interesting, Limited Human Data

Pterostilbene (Not Resveratrol) Emerging

Resveratrol was the darling of longevity science after a 2006 Nature paper showed it extended lifespan in obese mice via SIRT1 — but it hasn’t held up in humans: ~20% oral bioavailability, a ~14-minute half-lifehalf-life The time it takes for half a drug dose to clear the body. A longer half-life means less frequent dosing., and rapid gut metabolism into compounds of variable activity. Pterostilbene is the more defensible alternative — a methylated analog with ~80% bioavailability, a ~105-minute half-life, and blood-brain-barrier penetration. The human longevity evidence is still limited, but the pharmacokineticspharmacokinetics How a drug moves through the body — how it’s absorbed, spread around, broken down, and cleared. make it far more likely to reach target tissues at standard doses.

Dose: 50–150 mg/day, optionally with piperine (black pepper extract) for added bioavailability. A mechanistically sound bet with limited human outcome data — not yet at the Tier 1–2 standard.

Summary: The Longevity Protocol at a Glance

What This Protocol Doesn’t Include — And Why

Resveratrol: Poor bioavailability, disappointing human results. Pterostilbene is the rational alternative.

Rapamycin: The most evidence-backed longevity compound in preclinical models — but an immunosuppressantimmunosuppressant A drug that dials down the immune system, used after a transplant or for autoimmune disease. Some supplements can blunt or oppose it., prescription-only, and still under study (the PEARL trial). We don’t include prescription-only compounds here.

Metformin (for non-diabetics): The TAME trial is ongoing and will be definitive. Not yet supported for off-labeloff-label Prescribing an approved drug for a use the FDA hasn’t formally signed off on — legal and common, but less studied. longevity use as of 2026.

High-dose antioxidants (vitamin C, E, NAC in isolation): Largely negative longevity evidence — multiple large RCTs show null or adverse effects. The NRF2/sulforaphane approach (stimulating endogenous antioxidant production) is mechanistically superior.

Drug Interactions and Safety Considerations

How to Build This Stack Practically

Not everyone needs every supplement here. A phased approach:

Start here (Tier 1 foundation): Omega-3, Vitamin D3 + K2, Magnesium glycinate — the most common deficiencies and the strongest evidence-to-cost ratio.

Add creatine if: You’re over 40, you do resistance training, or you’re concerned about cognitive aging.

Add Tier 2 once the foundation is solid: Add NMN, Urolithin A, and Sulforaphane sequentially rather than all at once, so you can assess tolerance and individual response.

Test before and after where possible: Baseline labs — 25-OH vitamin D, omega-3 indexomega-3 index A blood test reporting EPA plus DHA as a percentage of the fatty acids in red blood cell membranes. It reflects intake reasonably well, but no trial has shown that treating to a target index improves health outcomes., fasting glucose, CRPCRP (C-reactive protein) A blood marker of inflammation made by the liver. The high-sensitivity version (hs-CRP) is used for heart-risk assessment., and a comprehensive metabolic panel — give you anchoring data. Repeat at 6–12 months to move from a generic protocol to a personalized one.