Following a request from the European Commission, the Panel on Dietetic Products, Nutrition and Allergies was asked for an opinion on the safety of synthetic trans-resveratrol as a novel food with a purity of ≥99% (w/w). The Panel considers that the information provided on the composition and specifications of the novel food is sufficient. The applicant intends to market the novel food as a food supplement in capsule or tablet form at daily doses up to 150 mg/day. The Panel considers that resveratrol does not have a nutritionally relevant role in the human diet and that the consumption of the novel food is not nutritionally disadvantageous. In accordance with the EFSA Scientific opinion on genotoxicity testing strategies, the Panel considers that the negative in vivo genotoxicity assay is sufficient to rule out the concern based on the positive in vitro chromosomal aberration tests. Reduced body weight gain is seen consistently in animal studies. On the basis of the BMDL05 of 344 mg/kg body weight (bw) per day derived from body weight data of female rats in a subchronic toxicity study and the intended intake of 150 mg/day, the margin of exposure is 172. For pregnant rats, it is below 62. Considering the weight of evidence, the Panel concludes that the intended intake level of 150 mg/day for adults does not raise safety concerns. The Panel notes that diarrhoea or other gastrointestinal symptoms were reported in four uncontrolled intervention studies at doses of 1 g resveratrol/day or higher. The Panel considers that the metabolite trans-resveratrol sulfate could inhibit CYP enzymes in humans and may interact with medicines which are mainly metabolised by CYP2C9. The Panel concludes that the novel food, synthetic trans-resveratrol, is safe under the proposed conditions of use.