Explore Supplements Subscribe
The VerdictLOW CONVICTIONWorth-It: Low ROI (45/100)

Real, small wins for some metabolic conditions — zero evidence for the longevity, anti-aging, or cognitive claims it's actually sold on.

If you bought resveratrol for "anti-aging" or longevity, ask one question tonight: do you have a confirmed metabolic indication (T2DM, NAFLD, metabolic syndrome, PCOS, or elevated CVD inflammation markers) and a doctor on board? If no, save your money — the human evidence for healthy-adult longevity use is zero.

Resveratrol is a plant defence molecule from grape skins (and Japanese knotweed, the cheap commercial source). Inside your cells it nudges a "low fuel" sensor called AMPK — sort of mimicking what happens when you eat less — which produces small, real metabolic effects in people who already have a metabolic problem. The wall almost no one mentions: less than 1% of what you swallow ever reaches your bloodstream as the active molecule, and dose-response curves actually flatten — and sometimes reverse — above ~500 mg/day. More is not better.

That's the general answer. Your stack is different.

Check your whole stack
SH
Dr. Seth Holbrook, DPT — Doctor of Physical Therapy • Coach to 300+ clients
I built The Verdict to cut through recycled health advice and show what the evidence actually supports.
Longevity / Polyphenol Conditional

Resveratrol

The $720 million longevity bet that quietly died — and the narrow places it actually still works.

Read

Tonight, ask yourself one question: do I have a confirmed metabolic indication — type 2 diabetes, fatty liver, metabolic syndrome, PCOS, or elevated CVD inflammation — and a doctor on board?

If yes, 150–500 mg/day trans-resveratrol with food is reasonable, with the standard monitoring labs at 12 weeks. If no — and you bought it for "anti-aging," longevity, or cognitive benefits — save your money. The human evidence for that use is zero.

Takes less than 2 minutes. No equipment needed.

The Verdict

Real, small wins for some metabolic conditions — zero evidence for the longevity, anti-aging, or cognitive claims it's actually sold on.

Resveratrol is a plant defence molecule from grape skins (and Japanese knotweed, the cheap commercial source). Inside your cells it nudges a "low fuel" sensor called AMPK — sort of mimicking what happens when you eat less — which produces small, real metabolic effects in people who already have a metabolic problem. The wall almost no one mentions: less than 1% of what you swallow ever reaches your bloodstream as the active molecule, and dose-response curves actually flatten — and sometimes reverse — above ~500 mg/day. More is not better.

  1. The verdict: Resveratrol shows MODERATE evidence for narrow indications — type 2 diabetes blood sugar, fatty liver, metabolic syndrome, PCOS, and CVD inflammation — at 150 to 500 mg/day. Outside these conditions, the evidence is null.
  2. What most people get wrong: A 2021 meta-analysis of human cognitive trials was titled "a cognitive enhancer for mice only?" — and the answer was yes. The "red wine for longevity" claim is mathematically broken: a 5 oz glass has 0.3–1.1 mg vs the 150–500 mg/day clinical dose. You'd need 150–500 glasses, and the alcohol gets you long before the resveratrol does.
  3. The protocol in plain English: For a real metabolic indication under medical care, start at 150–250 mg/day trans-resveratrol from a Polygonum cuspidatum (Japanese knotweed) extract, taken with food, daily, for at least 12 weeks. Skip the £30–£75/month "liposomal" or "phytosome" upgrades — there's no human outcome trial showing they work better.

Best for

Adults with confirmed T2DM, NAFLD, metabolic syndrome, PCOS, or elevated CVD inflammation markers — under physician oversight.

Skip if

Healthy adult buying for longevity / anti-aging / cognition. On warfarin, DOACs, chemo, or hormone-sensitive cancer therapy. Pregnant. Within 2 weeks of elective surgery.

Want the full evidence? Keep scrolling

The Protocol

Protocol illustration

If your indication is on the evidence map, the protocol is unglamorous: standard trans-resveratrol from a reputably-sourced Japanese knotweed extract, taken with food, daily, for 8–12 weeks before reassessing. Above 500 mg/day, multiple meta-analyses show the dose-response curve flattens or reverses — paying for premium-dose products buys diminishing returns, not bigger benefit.

Dosing

Population Dose Timing Duration Source
Adults with confirmed T2DM (glycemic adjunct) 150–500 mg/day (~half a clinical-dose capsule, daily) With food ≥8 weeks Zhu 2022; Jara-Palacios 2022
Adults with NAFLD 150–500 mg/day With food ≥12 weeks Elgebaly 2017; Liao 2023
Adults with metabolic syndrome 150–500 mg/day With food ≥12 weeks Tabrizi 2020
Women with PCOS (testosterone / HOMA-IR) 800–1000 mg/day With food, split AM/PM tolerable ≥12 weeks Hallajzadeh 2021
CVD patients with elevated inflammation 150–500 mg/day With food ≥8 weeks Koushki 2022
Healthy adults — anti-aging / longevity / cognition NO EVIDENCE-BASED DOSE — — No human outcome RCT
Older adults — cognitive protection / MCI NO EVIDENCE-BASED DOSE — — Marx 2021 meta null

Practical ceiling: 500 mg/day. Above this, dose-response flattens or reverses for nearly every measured endpoint, and GI tolerability drops above 1500 mg/day. There is no formal Tolerable Upper Intake Level.

Forms — head-to-head

Standard trans-resveratrol
Polygonum cuspidatum extract
The form used in every clinical trial with positive outcomes. Reputably-sourced knotweed = ~50% trans-resveratrol content.
£10–£25/month at 150–500 mg/day
+ Piperine combo
~1.5–2× plasma exposure
Reasonable bioavailability bump. Piperine inhibits glucuronidation. Outcome contribution unverified by isolation.
£15–£30/month
Liposomal / Phytosome
No human outcome RCT
Premium price, no superiority data over standard form at clinical indications. Marketing-heavy category.
£30–£75/month
Red wine
0.3–1.1 mg per 5 oz glass
150–500× below clinical dose. Mathematically incompatible with supplement-trial research. Alcohol load dominates.
Not a viable delivery vehicle

Absorption tips

Safety & Interactions

Safety illustration

Resveratrol's antiplatelet activity, CYP3A4/CYP2C9 inhibition, and phytoestrogen / SERM behaviour are the three reasons "it's just a polyphenol from grapes" understates the safety profile. Anyone on warfarin, DOACs, statins, immunosuppressants, hormone therapy, or chemotherapy needs medical oversight before starting.

Drug interactions

Warfarin / DOACs (apixaban, rivaroxaban) — Severe

Antiplatelet activity + theoretical anticoagulant potentiation. Case reports of altered INR with warfarin. Avoid or use only under hematology / cardiology oversight.

Statins, immunosuppressants, narrow-window CYP3A4 substrates — Moderate

Resveratrol inhibits CYP3A4 and CYP2C9 in vitro with documented but modest human relevance. Review concurrent medications; specialist consultation for narrow-therapeutic-index drugs (cyclosporine, tacrolimus).

Tamoxifen / Aromatase inhibitors / HRT — Moderate

Resveratrol acts as a phytoestrogen / SERM at some tissues. Theoretical interaction with anti-estrogen oncology therapy. Oncology consultation required.

Active chemotherapy (doxorubicin, cisplatin) — Moderate

Antioxidant activity may interfere with oxidative-stress-mechanism chemotherapy. Oncology consultation required — typically discontinue.

Antihypertensives (ACEi / ARBs / CCBs) — Low-Moderate

Additive BP-lowering effect, particularly in diabetic / cardiometabolic subgroups. Monitor BP for the first 4–8 weeks after initiation.

NSAIDs (naproxen, ibuprofen, aspirin) — Low-Moderate

Additive antiplatelet effect. Caution with concurrent regular use, especially pre-surgery.

Contraindicated populations

Side effects

EffectIncidenceDose-related?Action
GI distress (diarrhea, nausea)2–5% under 500 mg/day; substantial above 2 g/dayYes — dominant dose-limiting effectTake with food, split dose, or reduce
Mild liver enzyme elevationRare; NAFLD trials show improvement, not elevationNot typical under 1500 mg/dayBaseline LFTs if concerning history
Allergic reactionRare — grape / peanut cross-reactivity possibleNot dose-relatedDiscontinue
Headache / dizzinessUnder 3%UnclearOften transient; reassess at 2 weeks

Upper limit: No formal Tolerable Upper Intake Level set by EFSA, NIH, or IOM. Highest dose tested safely short-term: 5 g/day in oncology populations. Standard consumer doses of 150–500 mg/day are well tolerated.

Conviction

Low-to-Moderate (endpoint-stratified)

Real, narrow metabolic indications carry MODERATE conviction at 150–500 mg/day with food. The dominant consumer claims — anti-aging, longevity, cognitive enhancement, "biological age reversal" — carry no human outcome RCT support, and the cognitive claim has been actively debunked. The bioavailability wall (<1%), non-monotonic dose-response, and "red wine for longevity" math problem are HIGH conviction structural ceilings the marketing has spent two decades obscuring.

What would change this

A pre-registered RCT of ≥500 healthy 40–60-year-olds randomized to 150–500 mg/day trans-resveratrol vs placebo for ≥2 years, with hard primary endpoints (cardiovascular events, validated cognitive trajectory, epigenetic aging clocks), showing clinically meaningful benefit and independent replication. This trial does not exist. Until it does, the healthy-adult longevity claim is mechanism, not evidence.

Worth Your Money?

Weekly cost £2–£6 per week (standard 150–500 mg/day from a reputable Japanese knotweed extract). Liposomal / phytosome upgrades run £7–£18 per week and lack outcome data.
Worth it if You have a confirmed metabolic indication — type 2 diabetes, fatty liver, metabolic syndrome, PCOS, or elevated CVD inflammation markers — and your doctor is on board. The standard form is enough; skip the premium upgrades.
Lower priority if You're a healthy adult and you bought it for longevity or anti-aging. Your next £20 is almost certainly better spent on protein adequacy, sleep regularity, training consistency, and screening labs — these have outcome data resveratrol does not.
Conditional Value Skip — Healthy-adult longevity use

Go Deeper

Want to stop wasting money on supplements that don't survive their own clinical trials? The Verdict reviews one every week — free.

Subscribe to The Verdict

Key Sources

  1. Marx W et al. (2021). Resveratrol: A "miracle" drug in neuropsychiatry or a cognitive enhancer for mice only? A systematic review and meta-analysis. Neuropsychopharmacology. PMID 33303422. The definitive cognitive-debunk meta — human trials largely null despite consistent positive animal data.
  2. Liu Y et al. (2021). Fine wine or sour grapes? A systematic review and meta-analysis of the impact of red wine polyphenols on vascular health. Crit Rev Food Sci Nutr. PMID 32303823. Red wine polyphenols are NOT reducible to resveratrol; the longevity-via-wine claim fails the math.
  3. Zhu X et al. (2022). Effects of Resveratrol on Metabolic Indicators in Patients with Type 2 Diabetes: A Systematic Review and Meta-Analysis. Nutrients. PMID 35685602. T2DM glycemic control — FBS and HbA1c improved at 150–500 mg/day.
  4. Jara-Palacios MJ et al. (2022). Influence of Age and Dose on the Effect of Resveratrol for Glycemic Control in Type 2 Diabetes Mellitus: Systematic Review and Meta-Analysis. Adv Nutr. PMID 36014469. Lower doses (<250 mg/day) most effective; non-monotonic dose-response.
  5. Ashtary-Larky D et al. (2022). The Effect of Resveratrol on Blood Lipid Profile: A Dose-Response Meta-Analysis of Randomized Controlled Trials. Crit Rev Food Sci Nutr. PMID 36145131. Non-monotonic lipid dose-response — TC reduced at ≤500 mg/day, attenuated above.
  6. Elgebaly A et al. (2017). Resveratrol Supplementation in Patients with Non-Alcoholic Fatty Liver Disease: Systematic Review and Meta-analysis. Rev Recent Clin Trials. PMID 28338115. NAFLD — ALT, AST improved at 150–3000 mg/day.
  7. Fogacci F et al. (2019). Effect of resveratrol on blood pressure: A systematic review and meta-analysis of randomized, controlled, clinical trials. Crit Rev Food Sci Nutr. PMID 29359958. N=681, 17 RCTs. SBP reduced in diabetic subgroup; DBP NS overall.
  8. Hallajzadeh J et al. (2021). Efficacy of resveratrol in women with polycystic ovary syndrome: a systematic review and meta-analysis of randomized clinical trials. Phytother Res. PMID 37333786. PCOS — testosterone and HOMA-IR reduced at 800–1000 mg/day.

Action ROI

Is this worth your time, money, effort, risk, and trust for this goal? Different from Verdict Score (evidence strength) and Leverage Map (relative importance) — Action ROI is the worth-it call once friction is priced in.

Action ROI score
45/100 Low ROI Trust grade D
No - longevity has no human evidence, and the heart benefit only shows up in people who already have metabolic disease.
Time
Low
Money
Medium
Effort
Low
Risk
Medium
Why this score
Why it didn’t score higher
Best for
Lower ROI if
Minimum effective dose
150 to 500 mg/day of standard trans-resveratrol from Japanese knotweed extract, with food, for 8 to 12+ weeks, in a diagnosed metabolic indication only. More is not better above about 500 mg/day. For healthy-adult longevity there is no evidence-based dose.
Track this

Get the complete dosing protocol

Evidence-scored dosing, timing, forms, and who should skip it. One page, no fluff.

Get the protocol

Related free research

Supplements
Plant Sterols & Stanols — The Verdict
 Supplements
Exogenous Ketones — The Verdict
 Supplements
Serrapeptase — Does the Silkworm Enzyme Actually Work?

There are 424 more inside

Conviction-scored verdicts on supplements, nutrition, training, physio, and recovery.

Explore all Get weekly verdicts