Introduction PrEP has the potential to transform the HIV epidemic in the UK. BMSM experience a significantly higher HIV prevalence compared with other MSM meaning that PrEP rollout should be attentive to reducing health inequalities in this group. This research aims to describe the motivations and barriers to PrEP use for BMSM aged 18–45 in London.

Methods Twenty-five BMSM were recruited through social sexual apps for semi-structured interviews. All participants reported sexual behaviours consistent with PrEP candidacy. Interviews were transcribed verbatim and analysed using a thematic framework informed by inter-sectionality theory.

Results An ‘ideal’ PrEP candidate was frequently perceived to embody characteristics that participants themselves did not necessarily identify with (e.g. that they were insufficiently risky or sexually active to require PrEP). Many already felt marginalised by virtue of being both black and gay, or felt ‘type-cast’ as sexually dominant within the gay scene. Concern was expressed that taking PrEP may exacerbate such marginalisation by suggesting that they were also promiscuous. For others, however, taking PrEP meant avoiding another marginalised identity: that of someone with HIV. Participants tended to prefer conveniently located clinics outside of traditionally ‘black’ areas. Accessing services from staff of similar ethnic backgrounds was difficult for many, except for staff also perceived as gay.

Discussion Marginalisation remains a key barrier for this group, and should be considered when developing PrEP interventions. Existing services are acceptable for delivering PrEP interventions, but staff need to be mindful, sex affirmative and focus on developing rapport with BMSM of similar ethnic backgrounds as themselves.