This weekend, I found myself at an Endometriosis Awareness Month event and I realized how little I knew about this incredibly common yet understudied condition. It made me reflect on a broader issue as we marked International Women’s Day on March 8: why do so many women’s health concerns remain overlooked or misunderstood? One significant factor is the persistent underrepresentation of women in health studies and clinical research. Despite making up over half of the population, women still account for a disproportionately small percentage of research participants, leaving large knowledge gaps in how diseases manifest and how treatments work for half the population.
The roots of this disparity stretch back decades. In the 1970s, medical research commonly treated men’s bodies as the ‘default,’ and women’s physiology was too often dismissed as ‘atypical.’ A turning point came in 1977 when the Food and Drug Administration (FDA) instituted a guideline effectively excluding women of childbearing potential from early-phase clinical trials. Triggered by the tragic effects of thalidomide on pregnant women and their babies in Europe and Australia in the 1960s, this policy was intended to protect unborn children. Yet, in practice, it shut out nearly all premenopausal women (including those on birth control) from early-stage research. Only in 1993 did the U.S. Congress reverse this broad exclusion, mandating the inclusion of women in National Institutes of Health (NIH) – funded clinical trials. Given the United States’ dominance in health sciences research, accounting for more published clinical research than the next 10 leading countries combined, their policies have an outsized impact on global health studies, as these studies and policies influence medical standards worldwide.
However, lingering biases and institutional obstacles remain. Even after the policy change, the pace of progress has been slow. As recently as 2019, women still made up just 40 per cent of participants in trials for some of the diseases most likely to affect them, such as cancer, cardiovascular disease, and psychiatric disorders, according to a Harvard Medical School study. The risk of underrepresentation is not merely academic. Women experience adverse drug reactions at roughly twice the rate of men, likely because historically, dosages and protocols were tested primarily on male subjects. One study suggested that female patients receiving metal hip replacements faced a 29 per cent higher risk of implant failure than men, possibly due to anatomical differences that were insufficiently tested.
The problem is further compounded for women of colour. In many large clinical trials, researchers often fail to report outcomes by both sex and race, making it unclear how different groups actually respond to medical interventions. Danielle Mitchell, founder of Black Women in Clinical Research, points out that to recruit and retain a more diverse pool of participants, scientists must go beyond traditional methods. Building trust involves engaging communities in familiar settings, such as churches, salons, and neighbourhood centres and ensuring that research teams themselves are diverse.
As these conversations evolve, a key lesson emerges: When women are considered a ‘special population,’ their unique needs too often go unaddressed. The fact of the matter is that women make up the majority of the population. Giving women’s health the attention it merits is a global necessity and not a niche issue. Everyone gains from a more inclusive approach to research, which produces safer medical equipment, more effective treatment, and better health outcomes. International Women’s Day reminds us just how important it is to continue closing the gap — both in policy and practice — so that every voice, and every body, is properly represented.
