Resveratrol

What is resveratrol, and which foods contain it?

Resveratrol is a polyphenol found in plants. According to EFSA, it occurs naturally in grapes, grape juice and wine; amounts in peanuts, pistachios and blueberries are small. The same assessment notes that the highest proposed daily intake for supplements (150 mg) is about 50 times the intake from foods at a high percentile, and states that resveratrol has no nutritionally significant role in human nutrition. ^[9] That is, resveratrol is not a nutrient whose deficiency exists, as vitamins are; the supplement debate is a question of “added benefit”, not “deficiency”.

Resveratrol and the French paradox: is wine a source strategy?

The “French paradox” is the name given to the observation that coronary heart disease deaths in France are low despite high saturated fat intake. Renaud and de Lorgeril, who discussed this observation in The Lancet in 1992, proposed that the difference may partly arise from high wine consumption; the abstract of the article presents the effect of alcohol on platelet aggregation, not resveratrol, as the explanation. ^[1] This article is an observational, hypothesis-generating work; it does not show that resveratrol protects the heart.

Later data did not support the resveratrol story. In the InCHIANTI cohort of 783 people aged 65 and over in the Chianti region of Italy, resveratrol metabolites were measured in 24-hour urine. In 9 years of follow-up, the proportion who died was 34.4% in the lowest quartile of urinary resveratrol metabolites, 31.6% in the second quartile, 33.5% in the third quartile and 37.4% in the highest quartile (P = 0.67); the hazard ratio for death in the lowest quartile compared with the highest quartile was 0.80 (95% CI 0.54–1.17). Resveratrol level was also not significantly associated with inflammation markers, cardiovascular disease or cancer; the authors concluded that levels reached with a Western diet did not markedly affect health status or mortality risk. ^[2]

Wine has a further problem: according to the 2023 statement of the WHO Regional Office for Europe, current evidence does not show a threshold level at which the cancer-triggering effect of alcohol “turns on”, and there is no study showing that the possible benefit of light or moderate drinking on cardiovascular diseases and type 2 diabetes exceeds cancer risk at the same levels for individual drinkers. ^[11] For this reason, wine cannot be defended as a way of getting resveratrol.

Is resveratrol absorbed?

Absorption is high and bioavailability very low. In a study with labeled resveratrol in six volunteers, at least 70% of a 25 mg oral dose was absorbed; the peak blood level of resveratrol and its metabolites was about 491 ng/mL and the plasma half-life about 9.2 hours. However, unchanged resveratrol in plasma was below 5 ng/mL, that is, in trace amounts; most of the dose was excreted in urine. Sulfate conjugation, occurring very rapidly in the intestine and liver, was shown as the step limiting bioavailability. ^[3] As a result, the “unchanged resveratrol level in blood” is far lower than the concentrations used in cell and animal experiments; for this reason experimental findings cannot be carried over directly to humans.

Does resveratrol lower blood sugar?

The 2021 umbrella review, which combined meta-analyses of randomized trials for type 2 diabetes, metabolic syndrome and fatty liver, examined 11 meta-analyses in type 2 diabetes (1,476 people, 29 outcomes), 17 meta-analyses in metabolic syndrome (727 people, 26 outcomes) and 10 meta-analyses in fatty liver (271 patients, 24 outcomes). Beneficial effects of resveratrol had been reported on some outcomes such as blood pressure, lipid profile, glycemic control and insulin resistance; however, in nearly all outcomes the effect size was trivial, the certainty of evidence was very low to low, or the number of trials was small. Only in the short term (less than 12 weeks) was a clinically important effect of moderate certainty (GRADE) seen for HbA1c (mean difference −1.05%; 95% CI −2.09% to −0.02%; 6 trials). The authors concluded that current evidence does not support resveratrol supplementation for managing cardiometabolic risk markers in people with type 2 diabetes, metabolic syndrome and fatty liver. ^[4]

The confidence interval of the HbA1c finding nearly touches zero and rests on short, small trials. Evidence grade: C.

Does resveratrol lower blood pressure?

The 2015 meta-analysis by Liu and colleagues examined 6 trials (247 people in total). The overall result was that resveratrol did not significantly lower systolic and diastolic blood pressure. In a prespecified subgroup analysis, doses of 150 mg per day and above lowered systolic blood pressure by −11.90 mmHg (95% CI −20.99 to −2.81); there was no significant reduction at low doses, and meta-regression did not show a dose–effect relationship. The authors stated that more high-quality trials are needed for a causal conclusion. ^[5]

The subgroup result is not the main result: the overall effect was not significant. Evidence grade: D.

Is resveratrol good for postmenopausal bone density?

The RESHAW trial is a 24-month, double-blind, placebo-controlled RCT with a two-period crossover design examining the effect of resveratrol (75 mg twice daily) on cognitive function, cerebrovascular function, bone health and cardiometabolic markers in postmenopausal women. Participants were women aged 45–85 who were at least 12 months after menopause and not using hormone replacement therapy; people using insulin or warfarin were not enrolled. With 12 months of supplementation, compared with placebo, bone density increased in the lumbar spine (+0.016 g/cm²) and femoral neck (+0.005 g/cm²) and the bone resorption marker (CTX) decreased by 7.24%; in a sub-analysis the benefit was larger in participants who also took vitamin D and calcium supplements. 125 women completed the two-year trial. The trial was supported by a grant from the Australian National Health and Medical Research Council; a company that is a resveratrol manufacturer supplied the resveratrol and placebo capsules and additional funding (according to the authors the company had no role in design, analysis and writing); the authors declared no conflict of interest. ^[6]

The finding rests on a single RCT measuring bone density, not fracture outcomes, and needs confirmation. Evidence grade: C.

Does resveratrol extend life?

There is no study showing it extends lifespan in humans. The “longevity” story rests on animal experiments: in the 2006 study by Baur and colleagues, resveratrol brought the physiology of middle-aged mice fed a high-calorie diet closer to that of mice on a standard diet and increased survival; the same article reports that resveratrol had previously been reported to extend lifespan in yeast, worms and flies, and that this effect was proposed to depend on the Sir2 enzyme. ^[7] The mouse findings cannot be carried over to humans because of the low bioavailability described above and the result in InCHIANTI. ^{[3] [2]}

There is a warning regarding the safety of high doses: a phase 2 study of SRT501, a micronized resveratrol formulation developed by a pharmaceutical company, at 5.0 g per day in 24 patients with relapsed or refractory multiple myeloma (bortezomib was added if there was progression) was terminated early because of five serious kidney failure events. Kidney failure developed in the first two cycles when SRT501 was used alone; in three of the five patients creatinine was high before the first dose, in four the myeloma was progressing at that time, and all had nausea and vomiting beforehand. The authors stated that kidney failure is common in myeloma and the result may be specific to this disease; because of the dose used and the patient group, the study cannot be generalized to healthy people and is not a longevity study. ^[8]

Is resveratrol safe? Side effects and drug interactions

EFSA’s 2016 assessment concluded that the proposed use of synthetic trans-resveratrol up to 150 mg per day for adults does not raise a safety concern. The panel stated that in four uncontrolled intervention studies, diarrhea or other digestive symptoms were reported at doses of 1 g per day and above; that in studies lasting up to 3 months no treatment-related effects were reported at doses below 1 g/day, but that because the human studies had few participants, short duration and limited safety endpoints, these studies alone do not provide sufficient safety evidence. It also reported that the metabolite trans-resveratrol sulfate may inhibit CYP enzymes in humans and may interact with medicines metabolized mainly by CYP2C9. In this assessment the panel cites a study in which 42 healthy adults were given 1 g of resveratrol per day for 4 weeks, in which markers of CYP3A4, CYP2D6 and CYP2C9 activity were suppressed and that of CYP1A2 increased by about 16%. ^[9]

The EFSA warning does not name a specific medicine. The RESHAW trial excluded people using warfarin and insulin; therefore use together with these medicines was not examined in that trial. ^[6] Because of this potential interaction, the EU makes a warning for people using medicines mandatory on the product label (below). ^[10]

Animal data were also decisive in EFSA’s assessment: a consistent reduction in body weight gain was seen in rats; the margin of safety between the BMDL05 derived from body weight data in the subchronic study (344 mg/kg/day) and the proposed 150 mg/day intake was calculated as 172, and below 62 in pregnant rats. The panel nevertheless decided, based on the weight of evidence, that the proposed intake does not raise a safety concern for adults. ^[9] These calculations are an extrapolation from animal data to human intake; the same assessment explicitly states that human studies are short, small and have limited safety endpoints.

Is resveratrol supplementation legal? EU and Türkiye

EU. With Implementing Decision 2016/1190, the European Commission authorized trans-resveratrol to be placed on the market as a novel food ingredient only in food supplements in capsule or tablet form aimed at adults, at a dose of at most 150 mg per day; the decision refers to EFSA’s warning that there may be interaction with certain medicines and requires the label to carry a statement that people using medicines should consume the product only under medical supervision. ^[10]

Türkiye. Every food supplement must receive approval from the Ministry of Agriculture and Forestry. ^[12] The Ministry’s Food Supplements Restricted Substances List (21/09/2026 version) contains a limit of at most 150 mg per day in the adult population for synthetic resveratrol; the name “trans-resveratrol” is used on the label, and there is a statement that those under 18 should not use it and that people using medicines should use the product only under medical supervision (updated 03/07/2026). In a separate row for other sources — Japanese knotweed (Polygonum cuspidatum) and grape (Vitis vinifera) — the upper limit is 5 g/day for ages 11 and over (published 08/03/2016, updated 03/07/2026); it is stated that if use of these sources in food supplements before 31/12/2025 is proven, they will not be assessed as novel foods. The two rows belong to different source types; the 150 mg limit is for synthetic trans-resveratrol. ^[13]

Summary of the evidence

What questions should be asked when considering a supplement?

What outcome will it be used for: for blood sugar, blood pressure or bone goals the evidence is grade C and D, and no benefit has been shown for cardiovascular events and longevity. Is regular medication being used: medicines metabolized by CYP2C9 are important for interaction. Is there kidney disease or pregnancy: safety data for these groups are limited. Is the product approved in Türkiye: Ministry approval is product by product. This guide does not recommend personal doses; the decision to use should be made together with a physician and pharmacist.