Used in the treatment of HIV-1 infection, darunavir is an antiretroviral medication that belongs to the protease inhibitor class. It works by blocking the activity of the HIV-1 protease enzyme, which is essential for the virus to replicate. Darunavir is typically prescribed in combination with other antiretroviral drugs and is especially effective in patients who have developed resistance to other protease inhibitors. Due to its high genetic barrier to resistance, it is often used in both treatment-experienced and treatment-naïve individuals. The drug is usually boosted with a low dose of ritonavir or cobicistat to enhance its plasma concentration and prolong its effect. It plays a critical role in suppressing viral load, improving immune function, and reducing the risk of HIV transmission.