Background: Pterostilbene is an active molecule from the bark of the Pterocarpus marsupium tree with antioxidant and anti-inflammatory properties. Objective: This study aimed to evaluate the clinical safety of a standardized P. marsupium extract (PME) containing 90% pterostilbene (200 mg per day) in healthy adults. Methods: In a randomized, double-blind, placebo-controlled study, 60 healthy adult participants (27 males and 33 females) were randomized to receive PME-100 mg or placebo capsule twice a day for two months. The primary objectives of the study were to assess any changes in laboratory parameters, vital signs, and the occurrence of adverse events from screening to the final visit. Serum antioxidant enzyme levels were evaluated as a secondary outcome. Results: The hematological, lipid, glycemic, thyroid profiles and liver and renal functions remained within the normal range in all participants, with no difference between PME and placebo. Vital signs, including blood pressure, pulse rate, body weight, body mass index and electrocardiogram, did not reveal any significant differences between the PME and placebo groups at the beginning and end of the study. No serious adverse events were observed in any participant throughout the study period. The serum antioxidant profile was not significantly different between the treatment groups, although the glutathione levels were relatively higher in the PME group. Conclusions: Scientific evaluation of clinical safety of standardized extract is mandatory for its use as a supplement for various health benefits. The results of this study convincingly establish the safety of PME (>90% Pterostilbene) at 200 mg/day (100 mg bid) for human use. The study was approved by the Institutional Ethics Committee of BGS Global Institute of Medical Sciences & Hospital, Bangalore with the registration number CTRI/2019/08/020736.
Keywords: P. marsupium; adverse events; antioxidant; healthy adults; pterostilbene; safety.