For much of the 20th century, medical research was conducted largely through a male lens. Women were often excluded from clinical studies, reproductive health was treated as a private matter, and illnesses disproportionately affecting women received comparatively little scientific attention.Gloria Steinem did not create the women’s health movement, nor did she single-handedly transform medical research. But as one of feminism’s most influential public voices, she helped make women’s health a political issue and helped create the pressure for medicine and research institutions to change.Steinem’s campaign for reproductive rights placed control over women’s bodies at the heart of the feminist movement. She argued that access to contraception and abortion was not simply a social or moral question but fundamental to women’s equality.That argument helped shift reproductive health from the private sphere into public policy. The growing political movement around reproductive autonomy also encouraged greater attention to contraception, pregnancy, fertility and the health consequences of reproductive decisions. For Steinem, the underlying principle was straightforward: women could not have genuine equality without control over their own bodies.Menstruation: Breaking the silenceSteinem brought another neglected subject into public conversation: menstruation. Her celebrated 1978 essay, “If Men Could Menstruate,” used satire to expose the stigma surrounding periods and the cultural tendency to regard women’s biology as embarrassing or inconvenient.The essay was more than a feminist joke. By making menstruation discussable, Steinem challenged the silence surrounding menstrual symptoms and disorders. That mattered because conditions associated with menstruation had often been normalised rather than investigated.Her broader message was that women’s everyday physical experiences deserved to be taken seriously—and, ultimately, scientifically understood.Story continues below this adWomen’s pain: From dismissal to investigationThe women’s health movement gave political force to a common complaint: women were not always believed when they described pain.It helped shift the lens to conditions such as endometriosis, a chronic condition in which tissue similar to the lining of the uterus grows outside the uterus, often causing severe menstrual and pelvic pain, inflammation, and sometimes infertility. Endometriosis can cause severe pelvic pain, infertility and other complications, yet diagnosis has historically been delayed and the disease remains incompletely understood. In fact, earlier this year, Steinem spearheaded conversations around it.By challenging the dismissal of women’s bodily experiences, she helped establish the principle that women’s pain should be investigated rather than simply endured. That cultural shift helped create an environment in which neglected conditions could become legitimate research priorities.Challenging the male model of medicinePerhaps Steinem’s most important contribution was challenging the assumption that medical knowledge derived from men could simply be applied to women.Story continues below this adBy the 1970s and 1980s, women’s health advocates were exposing the consequences of women’s underrepresentation in research. The issue was not merely fairness: biological differences could affect symptoms, disease progression, drug responses and treatment outcomes.In 1986, the National Institutes of Health (NIH), the US agency for biomedical and public-health research, introduced a policy encouraging the inclusion of women in clinical research. In 1990, it established the Office of Research on Women’s Health, giving women’s health a permanent institutional presence within the nation’s leading biomedical research agency.The Women’s Health InitiativeThe new emphasis on women’s health produced large-scale research. In 1991, the NIH launched the Women’s Health Initiative, ultimately enrolling more than 150,000 postmenopausal women.The programme investigated major causes of illness and death among women, including cardiovascular disease, cancer and osteoporosis, while also examining the effects of hormone therapy and dietary interventions. Its scale was significant not simply because of the findings it produced, but because it demonstrated that women’s health questions warranted major, long-term scientific investment.Story continues below this adChanging the rules of clinical researchThe movement’s influence eventually became embedded in federal policy. The 1993 NIH Revitalization Act required women and minorities to be included in NIH-supported clinical research and required researchers to examine whether treatments affected different populations differently. This represented a fundamental change. Women’s participation in research was no longer merely encouraged as a matter of representation; it became part of the structure of federally funded clinical science. Steinem’s most important contribution to women’s health research was, therefore, indirect but profound. She helped turn women’s experiences — from reproductive choices to menstruation and bodily pain— into subjects of public debate and demands for institutional accountability. Her enduring message was ultimately a scientific one as much as a political one: Women’s experiences are evidence, women’s health questions deserve investigation, and women’s bodies cannot be understood adequately by treating men as the default patient.