Know2eat

Resveratrol

Isolated Compounds

What resveratrol may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedExercise performanceLimited evidence· 4 sources

Then, in order

About Resveratrol

A stilbene polyphenol produced by grapes, berries and Japanese knotweed as a defence compound. Nearly all commercial resveratrol is extracted from Polygonum cuspidatum root rather than from grapes.

Resveratrol is the cautionary tale of the whole supplement category. A 2003 paper reporting that it activated sirtuins and extended yeast lifespan launched an industry, a biotech acquisition and a decade of headlines about red wine. Then the human trials arrived and were, with few exceptions, null: no consistent effect on insulin sensitivity, inflammation, blood pressure or cardiovascular markers in healthy people, and a pharmaceutical development programme abandoned. Two findings deserve particular attention because they cut against the marketing. A trial in older men found that resveratrol blunted the improvement in cardiovascular fitness produced by exercise training, and a trial in postmenopausal women found it interfered with the bone response to exercise. Bioavailability is the underlying problem: oral resveratrol is absorbed and then almost entirely conjugated by the gut and liver, leaving vanishing amounts of the free compound in circulation.

Sold as
Capsule (trans-resveratrol), Tablet, Liposomal, Powder
Standardised to
Percentage trans-resveratrol, commonly 50–99% from Japanese knotweed — a product without this marker may not resemble what was studied.
Also known as
trans-Resveratrol, Japanese knotweed extract, 3,5,4′-trihydroxystilbene

Regulation: A dietary supplement in the US with no pre-market efficacy review. Marketing frequently references the red wine and longevity literature, which is observational and mechanistic rather than interventional.

What the research used

The amounts, forms and durations published trials of Resveratrol actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Metabolic and cardiovascular trials

    150–1000 mg

    Limited

    trans-Resveratrol capsule, daily · 4 weeks to 12 months

    A very wide dose range with no clear dose-response, largely because results across the range have mostly been null. Higher doses mainly produce more gastrointestinal complaints.

  • Studied for Pharmaceutical development programme

    2500–5000 mg

    Limited

    Micronised formulation, daily · Up to 29 days

    Doses used in the abandoned SRT501 programme. Nausea and diarrhoea were dose-limiting, and in one myeloma trial kidney problems led to the study being halted.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • With food

    Limited

    Usually taken with a meal for tolerability and because a standard breakfast increases absorption modestly in pharmacokinetic work. It does not fix the underlying problem, which is rapid conjugation after absorption rather than poor absorption itself.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Exercise performance

Muscle & Physical Performance
Limited evidence

This one runs against the marketing. In a randomised trial in older men, resveratrol taken during an exercise training programme blunted the improvement in maximal oxygen uptake and in vascular function compared with placebo, and a separate trial found interference with the bone response to exercise in postmenopausal women.

What may be going on: The transient oxidative stress of exercise appears to be part of the signal that drives adaptation. Blanketing it with a high-dose antioxidant may suppress the response — the same pattern seen with high-dose vitamins C and E.

Limited evidence. Early human work, or mostly lab and animal research.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Cardiovascular risk markers

Heart Health
Not enough evidence

Despite a large number of trials, resveratrol has not shown consistent effects on blood pressure, lipids or vascular function in humans. Meta-analyses that find small effects are dominated by small trials with high heterogeneity, and the largest individual studies are null.

Not enough evidence. Not enough human research to say anything useful yet.

View the 2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

DNA and cellular integrity

Cellular Health
Not enough evidence

The longevity story rests on yeast, worms, flies and mice, with the sirtuin-activation mechanism itself later disputed on technical grounds. No human study has measured anything resembling a lifespan or healthspan outcome.

What may be going on: Proposed activation of SIRT1 and AMPK signalling. The original assay used to demonstrate sirtuin activation was subsequently shown to depend on a fluorophore not present in the natural substrate.

Not enough evidence. Not enough human research to say anything useful yet.

View the 3 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Insulin sensitivity

Blood Sugar & Metabolic Health
Not enough evidence

Trials in people with and without type 2 diabetes disagree, and the better-controlled ones in non-obese participants found no improvement in insulin sensitivity. The animal data and the human data point different ways.

Not enough evidence. Not enough human research to say anything useful yet.

View the 4 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Interaction

    Inhibits drug-metabolising enzymes

    Interacts withCYP3A4, CYP2C9 and CYP1A2 substrates; warfarin; statins

    Resveratrol inhibits CYP3A4, CYP2C9 and CYP1A2 in human studies, which can raise blood levels of a long list of medicines including statins, some anticoagulants, immunosuppressants and calcium channel blockers. Anyone on regular medication should regard this as a genuine interaction rather than a theoretical one.

  • Worth knowing

    May work against exercise adaptation

    Two randomised trials found that resveratrol reduced the benefit people got from an exercise programme, on cardiorespiratory fitness in older men and on bone in postmenopausal women. If the reason for taking it is to support training, the available human evidence points the other way.

  • Too much

    Gastrointestinal effects at gram doses

    Nausea, cramping and diarrhoea are dose-limiting above about one gram daily. In one trial of a micronised high-dose formulation in myeloma patients, kidney problems led to early termination.

  • Avoid

    Oestrogenic activity is a question in hormone-sensitive conditions

    Resveratrol is a phytoestrogen with mixed agonist and antagonist behaviour in laboratory systems. What it does in a person with a hormone-sensitive cancer is unknown, which is a reason for caution rather than reassurance.

  • Worth knowing

    Source is knotweed, not wine

    Commercial resveratrol is extracted from Japanese knotweed root, which also contains emodin, an anthraquinone laxative. Products with lower purity carry more of it, which explains some of the loose stools attributed to resveratrol itself.

In the food catalogue

The whole-food form, where one exists. The evidence for a concentrated extract rarely transfers to the food, or the other way round — these are cross-links, not equivalents.

BlueberriesBerries contain small amounts of the same stilbene.Red grapesThe food most associated with resveratrol, though the amount in…

Evidence ratings on this page: 1 limited evidence, 3 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Resveratrol, or a dose to follow.