In the past the research community assumed that beyond the reproductive system, differences between males and females simply did not exist or were not relevant. Most medical research to date has been skewed to male physiology, putting women at risk for suboptimal care. The NIH Revitalization Act of 1993 was a critical milestone that mandated the inclusion of women in clinical research to improve health care for all. Unfortunately, nearly two decades later, only 37% of human studies include women and the data is even more concerning in animal and cell research, important precursors to human trials. There are several misconceptions of sex-based research regarding the cost of using both sexes, a sense of having to protect vulnerable women and/or a potential fetus, uniformity, avoiding the "complications" of the menstrual/estrous cycle, and the perceived complexity of recruitment of women. However, sex-and gender-based approaches to research and medicine frame important questions about the differences and similarities in men's and women's normal biological, behavioral, and social function in combination with their experience of the same diseases. The resources listed here are designed to support investgators, as they design and engage in sex-specific research.

Video Lectures: 

  • "Statistical Considerations for Sex Inclusion in Basic Science Research," 
    Dr. Denise M. Scholtens, Associate Director of the Division of Biostatistics, Associate Professor in the Department of Preventive Medicine, Northwestern University. 
  • "Considering Sex as a Biological Variable: The NIH Policy"  from the 2017 Sex Inclusion in Biomedical Research Workshop & Symposium 
    Dr. Teresa Woodruff, Founder and Director, Women's Health Research Institute, Vice Chair for Research 
    Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University
  • "Sex Influences on Brain and Body: An Issue Whose Time Has Comefrom the 2017 Sex Inclusion in Biomedical Research Workshop & Symposium 
    Dr. Larry Cahill
    Professor, Department of Neurobiology and Behavior, University of California, Irvine
  • "Incorporating Sex Into Your Research Agenda," from the 2017 Sex Inclusion in Biomedical Research Workshop & Symposium 
    Panel Discussion, Moderated by Dr. Francesca Duncan, Executive Director, Center for Reproductive Science
    Associate Research Professor, Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University

Animal Research Methods

A recent study by members of the WHRI of surgical journals found that in 618 studies when the sex of the study animals was reported, 80% used only male animals and 17% used only females. Read more

Cell Research Methods

In cell-based studies, 76% of the studies did not specify the sex of the cells, and when they did, 71% were male cells. Read more

Human Research Methods

While the inclusion of women in clinical research is essential to achieve sex-parity in research, an in-depth analysis using sex as a research variable is necessary to make a marked change in research design. Read more

Monthly Research Forums

Our Monthly research forums help dispel some of the misconceptions surrounding sex-based research and also features researchers and clinicians who practice sex-based research and care.  Read more

Women's Health Registry

The Illinois Women's Health Registry was created to assist with placing women into clinical trials. The registry is a comprehensive database where thousands of women are able to update their health information and may be recruited for research trials. Read more


External Resources and Publications 

Learn more about other organizations and societies that focus on sex inclusion and the promotion of women's health. In addition, the WHRI has compiled a list of publications and reports on the topic as well. Read more