Zambia's medicines regulator approved the HIV drug lenacapavir in just 12 days by using regulatory reliance, a streamlined approach that decomposes the approval process. Lenacapavir, a twice-yearly injection developed by Gilead Sciences, showed over 99.9% efficacy in preventing HIV infection and addresses adherence and stigma problems associated with daily oral PrEP. The rapid approval demonstrates how resource-constrained regulators in low- and middle-income countries can accelerate access to critical medicines.