Sexual consent is a central component in the primary prevention of sexual violence. There is growing evidence of the impact that alcohol consumption has on sexual consent. However, there has been no review examining sexual consent in the context of other drug-taking. Published literature was sought using searches of: PsycINFO, PsycARTICLES, Scopus, Web of Science, CINAHL, MEDLINE and Open Dissertations. Unpublished literature, such as unpublished government or charity reports, were identified through Google search engine. All 21 eligible studies employed qualitative or mixed methods; therefore, a thematic synthesis was deemed an appropriate method of analysis. Three themes were constructed: "Drug-taking changes sexual norms", "Drug-taking diminishes the capacity to make sexual decisions" and "Drug-taking reduces verbal and non-verbal ability to communicate consent". The findings demonstrated that prevailing models of sexual consent may not account for circumstances relevant to drug-involved sex, such as how drug-taking impacts freedom and capacity to consent to sex. We propose the use of the medical model of capacity to consent as a broader framework through which capacity to consent to sex in drug-taking contexts can be assessed. The importance of both the social and situational context for sexual decision-making following drug-taking is discussed.