The Gender Gap in Cannabis Clinical Trials

Time to read 2 min

The body’s mechanisms for managing stress, preserving energy, processing food, and overcoming pain, are profoundly impacted by our hormones. ⁠Yet most of the cannabinoid research is done only on male subjects. Why?!

In 1949, Dorothy Roe predicted that vitamin supplements would eventually allow women to grow to “more than six feet tall.” In the 21st century, Roe wrote, these supplements would replace all of our meals, and allow ladies to compete against men in football and prizefighting. These were some of the worst predictions about human development ever made, though they form part of a long tradition, running all the way to the present day, of women hearing less information, narrower insights, and stupider advice from health experts because of unchecked biases and institutional myopia. And while we might look down on the people who read Roe’s story seventy years ago, entire categories of research are still plagued by major gender imbalances.

A similar gap in understanding exists in the medical cannabis world. Acknowledgements are rare, but one example comes from last July, when the authors of a study about cannabis and mental health wrote that researchers had chronically “over-sampled males,” or “failed to report differences by sex.” Even if you aren’t looking to cannabis to treat menstrual cramps, menopause, or female fertility, you’re likely to major blind spots in the field. Ultimately, these can place serious limits on our understanding of cannabis’ effect on digestion, mood, cognition, or metabolism, as well as sexual health. 

While reports that focus on the gendered aspects of endocannabinoids are hard to come by, there are a few gems. A couple of years ago, a laboratory at Washington State University found that the presence of estrogen increased the pain-relieving effects of THC, and in March, a group at St. Louis University correlated marijuana use with increases in womens’ libido and improvement in orgasm, the idea being that the reward system was woken up by heightened dopamine levels during ovulation. This is supported by an earlier study that charted out a direct connection between the density of cannabinoid receptors and the presence of sex hormones.

Besides reports that focus directly on reproduction, the evidence also points to a difference in the emotional effects of cannabis on men compared to women. In 2010, for example, researchers found that cannabinoid-derived changes in food intake and energy balance were more pronounced in men, and that changes in mood were more visible among women. Differences in muscle and fat distribution could play a role in this, too, though a 2016 review linked most of the differentiation to “neurological sexual dimorphism.” In other words, the unique shapes of male and female brains almost certainly have a role in how either sex experiences the effects of cannabis.

All of this is pretty vague, of course. We’d all love it if the literature would even out, and there are signs that it’s starting to, but on the whole, medical cannabis research has some serious catching up to do. The human endocannabinoid system is tightly woven into the body’s mechanisms for managing stress, preserving energy, processing food, and overcoming pain, and with few exceptions, these mechanisms are profoundly impacted by hormones. There may come a day where everyone has access to flowers, concentrates, tinctures, and edibles that are tailor-made for the user’s sexual and hormonal makeup, based on the optimal strains, terpene profiles, and routes of consumption for men’s and women’s bodies. But that day is a long way off. Fifty years from now, our approach to medical cannabis might sound as silly and unappealing as food capsules replacing meat and potatoes.