Canadian Study Examines the Effects of High-Dose CBD

Researchers at the University of Montreal Hospital Center (CHUM) reported in late October 2026 that a single 200 mg oral dose of CBD produced a mild pleasant feeling in healthy adults.

The results come from a clinical trial published in the Journal of Psychopharmacology. The team, which included Lucy A. Chester and Dr. Didier Jutras-Aswad, recruited 70 healthy adults who use cannabis from time to time.

Each volunteer took oral doses of synthetic CBD at 20, 50, 100 and 200 mg, plus a placebo, in a randomized, triple-blind, crossover design. All doses were given right after a high-fat meal. The researchers recorded how participants felt, along with heart rate, blood pressure and breathing rate.

At 200 mg, the peak score for a “pleasant effect” averaged 12.8% above placebo. The difference was statistically significant, though the feeling itself was modest. Lower doses showed no meaningful change, most other self-reported measures stayed the same, and side effects were mild or moderate. According to the authors, a single dose of 100 mg or less is unlikely to produce a noticeable effect in healthy occasional users under the same conditions.

The study tested one-time doses of a purified isolate taken with fatty food, which can boost absorption. Daily cannabis users, or people taking CBD on an empty stomach, may respond differently.

Dr. Didier Jutras-Aswad, a psychiatrist and researcher at the University of Montreal, said that the findings “could initially call into question the notion that cannabidiol is not at all psychoactive.”

He added that the team did detect some psychoactive effects at the top dose. The researchers stress that the sensation is subtle and nothing like the high linked to THC.

For years, CBD has been described as the non-intoxicating cannabinoid, in contrast to THC. A 2018 World Health Organization review found no signs of abuse or dependence potential for CBD in humans, and the 2018 US Farm Bill removed hemp with no more than 0.3% THC from the federal controlled substances list.

The trial is part of a wider program at CHUM’s Living Cannabis Laboratory, a controlled research space where scientists study how cannabinoids affect the body, thinking, and behavior. Its work also adds to research on the endocannabinoid system, the receptor network that CBD and THC interact with.