Marijuana sources in a medical marijuana environment: dynamics in access and use among a cohort of young adults in Los Angeles, California.

While a range of sources exist for marijuana users to acquire marijuana for medical or personal use, prior research on marijuana sources primarily focused on single sources. In this analysis, we longitudinally examined characteristics of multiple sources selected by marijuana users, motivations to use sources, and how a blend of marijuana sources accommodated users' needs. Young adult marijuana users (n=60) in Los Angeles, CA, where marijuana has been legal for medical use since 1996, completed two annual qualitative interviews on marijuana use practices and sources between 2014 and 2016. Approximately two-thirds were medical marijuana patients and one-third were non-patient users. Participants reported acquiring marijuana from the following primary sources across two interviews: dispensaries and delivery services, private sellers in the illicit market, friends and family, and marijuana events/conferences. While patients with legal medical access to marijuana typically purchased marijuana from dispensaries or delivery services, they often supplemented from other illicit sources. Non-patients often accessed marijuana through dispensary diversion but also other sources. As patients became non-patients and vice versa during the study period, source type changed too. Broad access to marijuana via legal and illicit sources in this sample is indicative of societal trends towards normalization of marijuana use.