evidence: Recreational drug use is common among MSM who engage in high-risk sexual behavior [12–14]. One of the most commonly used recreational drugs is nitrite inhalants (amyl nitrite, butyl nitrite, isobutyl nitrite; commonly referred to as ‘poppers’) [15,16]. Previous studies have reported significant associations between popper use and higher rates of high-risk sexual behavior and more frequent acquisition of HIV [12,14,15,17–19]. Despite their potential for harmful effects at high doses [15,16,20–22], popper use remains prevalent among MSM around the world, ranging from 20–40% among MSM cohorts in the United States, Canada, United Kingdom, and China [12,14,19,23–26]. Unlike stimulants and other recreational drugs that correlate with high-risk behavior among MSM, poppers have transient immunosuppressive effects in animal models, particularly at high doses with frequent exposure [21,27–29]. Poppers gained notoriety early in the AIDS epidemic as a potential cause of AIDS and Kaposi sarcoma [16,30], but these notions were later debunked [31,32]. Thereafter, poppers were associated with increased risk of Kaposi sarcoma in some pre-HAART cohorts [33–35], although other studies did not find this association [23,36]. In subsequent studies, popper use was associated with risk of HHV-8 seroconversion or anal cancer precursor lesions among HIV-uninfected MSM [37–39].