Given significant differences in the number of female participants in clinical trials and the amount of research on certain diseases in the female body, it is important to understand the factors that contribute to these inequities. Read more to uncover the major causes of such inequalities.
Legislation
Although women have historically been underrepresented in clinical trials, this inequity was further exacerbated by the Food and Drug Administration in 1977: unless they faced a life-threatening condition, women of reproductive potential were not allowed to take part in Phase 1 and 2 clinical trials.
This law was largely due to an incident known as the thalidomide tragedy, when pregnant women who were given a drug for morning sickness gave birth to babies with severe limb defects. As a result of not wanting to bring harm to pregnant women, the FDA passed the 1977 law.
Alarmingly, Congress did not mandate women’s inclusion in clinical trials in the U.S. until 1993.
Historical Views of Women
Women have clear biological differences, like hormone cycles, fat distribution, and metabolic rates, that make their bodies interact with medications in certain ways. However, the medical system has a history of treating women like ‘smaller men’ or assuming that men’s bodies are the norm and comparing the bodies of women to those of men as a result.
It was also thought that a woman’s hormone fluctuations made her too complex to study in biomedical research.
Lack of Funding
In 2020, only 1% of funding for healthcare research, aside from oncology research, was allocated to women’s health, while diseases that affect men received double the funding of those affecting women within the U.S.
Without funding for female-specific health conditions, no research can be done.
Lack of Female Primary Investigators
The Journal of the American College of Cardiology conducted a study on 620 cardiovascular clinical trials between 2010 and 2019. They found that studies led by female researchers were more likely to enroll female participants.
However, despite cardiovascular disease being the leading cause of death of women in the United States, only 18.4% of those trials were led by women, indicating that there was far less research on women being conducted by women during the entire decade.
It has been found that female researchers are more likely to study female-specific diseases. Additionally, trials led by female investigators are more likely to have women as staff. Research staff are responsible for patient interaction and often recruiting participants, which can play a role in enrolling female participants.
Sources:
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Gupta, Harsh, et al. “Clinical Trials Have a Gender Problem.” TIME, 16 Oct.
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“History of Women in Clinical Trials.” Medidata, 8 Mar. 2025, http://www.medidata.com/
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