The process of informed consent is fundamental to basic scientific research with human subjects. As one aspect of the scientific enterprise, clinical drug trials rely on informed consent documents to safeguard the ethical treatment of trial participants. This paper explores the role of heteronormative assumptions within this process, postulating the ways in which the biomedical texts that make up the informed consent process may render gay, lesbian, and non-binary gender-identifying participants discursively invisible. We argue that trial criteria and informed consent practices may reproduce a binary sex and gender system in which ‘male’ and ‘female’ subjects are presumed to identify as heterosexual and engage in procreative sex. This binary is not one of equivalence as female subjects who are able to have children may be wholly excluded or excessively controlled in studies while male subjects are merely admonished to use medically sanctioned birth control methods. Furthermore, we claim that the assumption of procreative heterosexual behaviors may pervade the informed consent process and the mundane practices of biomedical research more broadly. Given that these assumptions have important implications for risk and inclusivity in clinical trials, in the last part of this paper we outline directions for future research on the reproduction of heteronormativity in scientific discourse and practice. Keywords: heteronormativity, biomedical research, clinical trials, gender binary, scientific discourse.