Women Are Being Excluded From Clinical Trials

"Complexities of the menstrual cycle" are to blame

Female Jogger on Coleman Avunue in Morro Bay, CA 5-2-07 - Photo by Mike Baird https://bairdphotos.com Canon 20D 100-400mm IS lens handheld from an outrigger canoe. Michael "Mike" L. Baird

It’s not hard to think of jobs and positions that women have been barred from in the past because of their sex – doctors, scientists, astronauts, even professional athletes. But an editorial out this week in the British Journal of Sports Medicine adds a new modern day position to the list: clinical trial participant.

Even though sex-based equality has progressed in other fields, women have been routinely excluded from clinical trials, the group of British and American experts say, though medical problems and treatments affect them equally, if not more.

Some studies have shown that women are twice as likely to suffer from adverse reactions to drugs, and 80 percent of drugs are withdrawn from the market due to unacceptable side effects in women.

The group cites a study from 2014, where researchers reviewed nearly 1400 sports and exercise research studies involving six million people over three years. Those researchers found that only 39 percent of those study participants, just slightly more than a third, were women.

Researchers are frequently excluding women from trials due to “complexities of the menstrual cycle,” the scientists say. To conduct studies without possible interactions from fluctuating hormones, many researchers forgo using women participants. Or when they do, they use them in early follicular stages of the menstrual cycle, when hormones are lower and more equivalent to male levels.

This leads to little understanding of how differing hormone levels would affect experiments, say the researchers. It is unknown if the hormone levels would affect each experiment at all, because they have not been tested. And this does not represent the real world that women live in, where hormones fluctuate cyclically. The scientists say this requires more research.