The National Institutes of Health wants clinical trial researchers to start recruiting female lab animals. The New York Times reports that the NIH warned scientists that they can no longer avoid having to cope with reproductive cycles and hormone fluctuations.

The NYT notes that it has taken a long time to raise the number of women participating in human clinical trials, and that men continue to dominate trial populations.

The NYT also notes that statins were mostly tested in men, and “evidence of their benefit in women is limited.”

“One of the underlying assumptions has been that females are simply a variation on a theme, that it isn’t a fundamentally different mechanism. . . we’ve discovered that’s not always the case,” a University of Michigan research scientist told the Times.