BACKGROUND: Use of amphetamine-type substances (ATS) has been linked to increased risk of HIV and other sexually transmitted infections (STI) worldwide. In Cambodia, recent ATS use is independently associated with incident STI infection among young female sex workers (FSWs). METHODS: We conducted 33 in-depth interviews with women (15-29 years old) engaged in sex work to explore ATS use and vulnerability to HIV/STI. RESULTS: Participants reported that ATS, primarily methamphetamine in pill and crystalline forms (yama), were cheap, widely available and commonly used. Yama was described as a "power drug" (thnam kamlang) which enabled women to work long hours and serve more customers. Use of ATS by clients was also common, with some providing drugs for women and/or encouraging their use, often resulting in prolonged sexual activity. Requests for unprotected sex were also more common among alternatives intoxicated clients and strategies typically employed to negotiate condom use were less effective. CONCLUSION: ATS use was highly functional for young women engaged in sex work, facilitating a sense of power and agency and highlighting the occupational significance and normalization of ATS in this setting. This highly gendered dynamic supports the limited but emerging literature on women's use of ATS, which to date has been heavily focused on men. Results indicate an urgent need to increase awareness of the risks associated with ATS use, to provide women with sustainable alternatives for income generation, to better regulate the conditions of sex work, and to work with FSWs and their clients to develop and promote culturally appropriate harm reduction interventions.
