Women’s health Research

What is women’s health research?

Women’s health research is the study of health across a woman’s lifespan in order to preserve wellness and to prevent, diagnose, and treat disease. It includes all health conditions for which women and men experience differences in risk, presentation, and treatment response, as well as health issues specific to women, such as pregnancy and menopause.

Women’s health research considers both sex and gender differences and how these differences affect disease risk, pathophysiology, symptoms, diagnosis, and treatment.

Sex vs. gender

What’s the difference?

While the terms sex and gender are often used interchangeably in society, they have distinct definitions that apply in scientific research. Both sex and gender are variables that should be considered in scientific research, from the development and design of studies to the analysis and reporting of study results.


is a multidimensional biological construct based on anatomy, physiology, genetics, and hormones. These components are sometimes referred to together as “sex traits.”


is broadly defined as a multidimensional construct that encompasses gender identity and expression, as well as social and cultural expectations about status, characteristics, and behavior as they are associated with certain sex traits. Understandings of gender vary throughout historical and cultural contexts.

the health gap for women

Until about 25 years ago, essentially all health research was conducted on men.

Women were actively excluded from participating in most clinical trials. Why? Because of the persistent idea that female hormonal cycles were too difficult to manage in experiments — including the fear of harming potential pregnancies — and that using only one sex would reduce variation in results. This exclusion of females in health research wasn’t just limited to humans. It extended to research on female animals, cells, and tissue. Researchers assumed that they could simply extrapolate their male-only study results to females, a dangerous precedent that overlooked fundamental differences between women and men.

Fortunately, thanks to advocacy by the Society for Women’s Health Research and other groups, Congress passed the National Institutes of Health Revitalization Act of 1993, mandating the inclusion of women and minorities in NIH-funded clinical trials. In the same year, the Food and Drug Administration changed its policies to require the inclusion of women in efficacy studies and in the analysis of data on sex differences.

Then, in 2016, the NIH implemented a new policy stating that sex as a biological variable should be factored into preclinical research and reporting in vertebrate animal and human studies. Today, all NIH-funded researchers must either include both female and male research subjects or explain why they do not.

Although researchers have been playing catch-up for the past couple of decades, this longtime bias put the health of women at risk and created a huge gap in knowledge about women’s health and the role that differences between women and men play in health and disease. 

Differences exist

The biological differences between women and men go beyond basic anatomy. Researchers must consider sex differences down to the cellular level in order to discover crucial information about the varied development, function, and biology between women and men.


of women with
sleep apnea
go undiagnosed

because they may not report the same “textbook” symptoms as men.


of those with
Alzheimer’s disease
are women

and some research suggests women are at greater risk for AD than men.


of people with
are women

and they experience rapid bone loss at menopause due to hormonal changes.


The Inclusion of Women in Research

1977 · The Food and Drug Administration (FDA) bars women of child bearing potential from participating in most early phase clinical research.

1985 · A United States Public Health Service task force concludes that exclusion of women from clinical research was detrimental to women’s health.

1986 · The National Institutes of Health (NIH) adopts guidelines urging the inclusion of women in NIH-sponsored clinical research.

1990 · The Society for Women’s Health Research is founded and asks the General Accounting Office (GAO) to examine whether NIH is following its 1986 guideline.

1990 · A GAO report reveals that the NIH guidelines are not being followed. The Physician’s Health or “aspirin” study, designed to examine the impact of taking aspirin on cardiovascular disease, is one of many large studies not included women highlighted by the report.

1993 · The NIH Revitalization Act of 1993 mandates that the NIH must ensure that women and members of minorities and their subpopulations are included in all human subject research.
1993 · The FDA rescinds earlier guidelines barring the participation of women with child-bearing potential from most early phase research.

2000 · The GAO concludes that although women are now included in clinical research proportionate to their representation in the population, analysis by sex of subjects is rare.

2001 · The GAO concludes FDA not effectively monitoring research data to determine how sex differences affect drug safety and effectiveness.

2006 · The Organization for the Study of Sex Differences is established. It is the brain child of basic and clinical scientists with established research commitments to the study of sex differences, and staff members of SWHR.

2012 · Food and Drug Administration Safety and Innovation Act (FDASIA) signed into law, requiring FDA to provide a special report and accounting of trials by sex, race, and ethnicity.

2014 · The National Institutes of Health (NIH) enact new policies to address sex differences by will be requiring applicants to report their cell and animal inclusion plans as part of preclinical experimental design.

2015 · The FDA launched the website Drug Trials Snapshots that provide consumers with information about who participated in clinical trials that supported the FDA approval of new drugs. The site is is part of an overall FDA effort to make demographic data more available and transparent.

2016 · NIH implemented a policy that expects scientists to account for the possible role of sex as a biological variable (SABV) in vertebrate animal and human studies.

Both sex and gender influence health across the lifespan, and SWHR strives to comprehensively address both sex and gender as they relate to women’s health. When citing research, SWHR uses terminology consistent with what is used in the cited study. As inclusive language practices continue to evolve in the scientific and medical communities, we will reassess our language as usage to promote accuracy and inclusivity. Please note that not all language will be updated retroactively.  

SWHR acknowledges that there are valued groups of people that may benefit from our materials who do not identify as women. We encourage those who identify differently to engage with us and our content.