Concepts of illicit drug quality among darknet market users: Purity, embodied experience, craft and chemical knowledge.

BACKGROUND Users of darknet markets refer to product quality as one of the motivations for buying drugs there, and vendors present quality as a selling point. However, what users understand by quality and how they evaluate it is not clear. This article investigates how users established and compared drug quality. METHODS We used a two-stage method for investigating users' assessments. The user forum of a darknet market that we called 'Merkat' was analysed to develop emergent themes. Qualitative interviews with darknet users were conducted, then forum data was analysed again. To enhance the applicability of the findings, the forum was sampled for users who presented as dependent as well as recreational. RESULTS Quality could mean reliability, purity, potency, and predictability of effect. We focused on the different kinds of knowledge users drew on to assess quality. These were: embodied; craft; and chemical. CONCLUSION Users' evaluations of quality depended on their experience, the purpose of use, and its context. Market forums are a case of indigenous harm reduction where users share advise and experiences and can be usefully engaged with on these terms.