Women's psychological reactions are known to differ from men's, and it is widely believed that women respond more strongly to alcohol and drugs. We used to think the reason was that women's bodies are smaller, so the same amount gives a higher concentration in the blood. A new study suggests the effect on women is stronger even when the level in the blood is the same as in men. One of these substances is psilocybin, the compound in some hallucinogenic mushrooms, which is being considered as a treatment for some mental illnesses.
The study was carried out by a team at Maastricht University in the Netherlands, led by Mason, a researcher who specialises in how drugs affect the brain and behaviour. The researchers pooled data from two trials with 72 healthy volunteers, 40 women and 32 men, all of whom had used psychedelics before (substances that change how people perceive things and think). The volunteers were given laboratory-made psychedelics.
The first trial compared psilocybin with another substance called 2C-B, which alters perception and mood. Participants took both substances and an inactive placebo on separate days. The second trial tested LSD against a placebo. Neither the volunteers nor the researchers dealing with them directly knew which substance each person had taken, to keep expectations from affecting the results.
Participants rated their feelings and the effects during the sessions and answered questions about their experiences afterwards. The researchers also took blood samples to measure how much of each drug was in their bodies. The results were released in 2026 as a preprint on bioRxiv.
Women reported feeling more strongly under the influence, and they felt less alert and less in control of their thoughts. The difference in the overall feeling of the drug's effect was clearest with psilocybin. The drop in alertness differed significantly with psilocybin and 2C-B, but not with LSD. Tests of understanding and responding emotionally to other people's feelings showed no important difference between the sexes.
The researchers tried to explain the results by body weight, because everyone got the same fixed dose regardless of weight. Since the women in the study were generally lighter, their blood levels were expected to be higher. The blood tests did not support this: there was no important difference between women and men in the peak blood level of the drugs, nor in how long they stayed measurable.
The researchers suggest that female hormones such as oestrogen may play a role. Psychedelics act on nerve signals that rely on serotonin (a chemical that helps brain cells pass messages to each other), and oestrogen can also affect how these signals work.
The team did not measure hormone levels in the women or take the menstrual cycle into account, so it cannot say whether hormones are really behind the differences. The two trials were also not designed to study differences between men and women, and they were fairly small. Larger studies are needed to confirm the findings before treatment doses of these drugs are adjusted.
Like
Love
Angry
Dislike
