Used in HIV prevention, particularly in long-acting vaginal rings for women. The ring slowly releases dapivirine over a month, providing a sustained barrier against HIV transmission. It serves as a user-controlled, discreet option in regions with high HIV prevalence, especially where condom use is limited. Investigated in clinical trials showing significant reduction in HIV infection rates. Also explored in combination with other antiretrovirine drugs for enhanced efficacy. Not used as systemic treatment but focused on topical pre-exposure prophylaxis (PrEP).