‘Women are underrepresented in clinical trials’ is a statement heard frequently despite several decades of attention and regulatory initiatives to improve their representation. It is therefore a relevant question to consider whether the existing EU regulation is sufficient to promote representation of sexes. This article revisits the regulatory approaches in the EU and the US to address the inclusion of sexes in clinical trials for new medicinal products, and reviews the extensive literature and data available on the subject. The article does not find that introduction of a specific requirement to include women in clinical trials in EU regulation is necessary to address issues of underrepresentation. There are already several regulatory instruments at hand to address representation. However, there are fundamental issues of how to define and assess representativeness at various stages of development in academic and industry led trials that calls for further discussion and analysis.