Anabolic-androgenic steroid testing as a tool for consumer engagement and harm reduction: a sequential explanatory mixed-method study. - Piatkowski, Timothy; Coomber, Ross; Francis, Cameron; Kill, Emma; Davey, Geoff; Cresswell, Sarah; White, Alan; Harding, Madeline; Blakey, Karen; Reeve, Steph; Walters, Brooke; Puljević, Cheneal; et al. (Harm Reduction Journal, 2025)