Science & Research

Understanding Sex Differences

What is a sex difference?

According to the Institute of Medicine Report Exploring the Biological Contributions to Human Health: Does Sex Matter?, a sex difference is defined as a difference due to the sex chromosome or sex hormones. Gender refers to a difference between men and women that occurs due to cultural or social variations in a particular sex. As it will often not be clear whether an observed difference in safety or efficacy is due to gender or sex, the FDA has used the terms interchangeably to describe any difference--cultural or social, genetic or hormonal--between males and females.

What is the FDA doing to promote a better understanding of sex differences?

Research has shown that sex as a variable contributes to differences in the safety and efficacy of drugs, biologics, and devices. To better understand the biologic basis for sex differences, the FDA Office of Women’s Health (OWH) advocates for the participation of women in clinical trials, supports scientific research within and outside the FDA, and provides training and other resources for health professionals.

Regulations and Guidance Documents on Research on Sex Differences

Page Last Updated: 07/19/2016
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