NIH Now Requires Scientists to Test New Drugs on Male and Female Animals

The National Institutes of Health (NIH) announced last week that researchers and scientists are now required to test new drugs on both male and female laboratory animals to gather all possible information regarding both sexes.

For years, experimental drugs were tested solely on male laboratory animals because researchers feared that the reproductive cycles and hormone fluctuations of the female animals would cloud the results of the experiment. In essence, the strategy is viewed more as a shortcut to getting the desired results faster.

"The sex of the cell makes a huge difference [in experiments] because the preclinical studies, where we're testing drugs or therapies are those studies that build the evidence base and inform the clinical studies," said Dr. Janine Clayton of the NIH, in this PBS newscast. "So if you're going to be studying a disease that affects both men and women, it's really important to think about males and female cells and males and females in the animal model work."

Female cells can greatly influence research findings because there are sex differences when it comes to any given disease. For example, males have a four to five times higher a risk to develop autism spectrum disorder due to differences in one's neurons. So when conducting an experiment to search for a cure or treatment for autism, it's important to document findings for both sexes because it's certainly relative.

The neglect of female animals is also remains an issue because women make up more than half of the participants in clinical research, but they are underrepresented in clinical trials conducted by drug companies and other manufacturers. Recent studies have shown that women experience more serious side effects from new treatments, according to the New York Times.

As a result, and despite "being known within a certain portion of the research community ... and there being a lot of pushback," according to Phyllis Greenberger of the Society for Women's Health Research, the National Institutes of Health are now focused on developing policies to have these new regulations take effect by October of 2014.