Dhivya Ramalingam, Ph.D. 

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Tags:  Sex differences, THC, smoking, young adults.

 

The problem:  There are gender-specific differences in the metabolism of cannabis. Women may have more serious consequences of cannabis than men. However, there are not many studies in humans to address this problem. 

 

Why do this study?   The aims of this study were to understand gender-specific differences in the metabolism of cannabis and differences in the acute effects of cannabis on women versus men.

 

The study:  This study enrolled 91 participants, aged 19 to 25 years, who were regular cannabis smokers. These participants were randomly assigned to smoke either a cannabis cigarette with 12.5% THC (THC is the high-inducing component in cannabis) or placebo (< 0.1% THC). After adjusting for one withdrawal, there were 43 men and 17 women in the THC group; 21 men and 9 women in the placebo group. Participants were asked to smoke the cigarette for a maximum of 10 minutes. Researchers measured vital signs, blood levels of THC and two THC metabolites  (10-OH-THC, THC-COOH) content and participants’ ratings of their subjective mood effects from a scale of 0 to 100.  Data was collected at baseline and in 6-hour increments.

 

The study found that women smoked significantly less of the cannabis cigarette than men did. The blood THC concentration in women was lower than that of men even after adjusting for the amount inhaled. Despite the lower level of blood THC in women, there were no sex-specific differences in subjective effects between men and women.

 

Conclusions:  Women seem to achieve the same acute effects of cannabis as men do with a much lower blood THC concentration.

 

What does this study add? Previous studies that have explored the gender-specific differences in cannabis metabolism have mostly been performed in rodents. However, it was unclear whether the same differences exist in humans. The current study, performed under controlled conditions in humans, shows that cannabis is indeed metabolized differently in humans, with women attaining the same “high” with a much lower dose of THC in their blood.

 

Funders:  Canadian Institutes of Health Research, Canada Foundation for Innovation, National Institute on Drug Abuse Drug Supply Program and University of Toronto

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Author conflicts:  None

 

Commentary: The work lends support to the notion that cannabis may be metabolized differently between women and men. The results from this study contradict those from prior studies where no gender-specific differences were seen in the acute effects of cannabis. One possible explanation for this discrepancy could be due to the design of the studies themselves. Previous studies required the participants to inhale a specified amount of cannabis, whereas the current study did not. Results from this study should be interpreted with caution because no adjustments were made for menstrual cycles or history of cannabis use, for instance, among the participants.