evidence: In particular, information is lacking on the individual and social experience of young people with HIV who use poppers and whether poppers influence HIV care outcomes (such as viral suppression). The limited availability of current data underscores the rationale for our current study, indicates that poppers are often overlooked, minimized or under assessed by researchers and clinicians as drugs of abuse, and little is understood about social and environmental contexts for use. Even medical providers with experience providing HIV and addiction care to MSM may not be aware of the risks of popper use [27]. Speculation early in the epidemic that popper use caused AIDS or Kaposi sarcoma has been disproven [28, 29], but gaps remain in our knowledge of their mechanism for HIV risk. There is some evidence that popper use among persons living with HIV is associated with immunosuppression [30, 31] and elevated cancer risk [32], but a richer understanding of the context for behavioral risks associated with popper use is needed and represents an unmet opportunity to reduce new HIV transmissions. Further, the impact of popper use on HIV care engagement (e.g., attending medical visits) and treatment adherence is unknown.