A microneedle (MN) patch that transdermally deliver liquid-phase therapeutics enable direct use of approved liquid drugs without the additional solidification, efficacy verification, and subsequent approval. Dissolving or coated microneedle that deliver reformulated, solidified therapeutics have considerably advanced; however, microneedles that can deliver liquid drugs still remain elusive because of technical limitations. We present a snake fang–inspired microneedle patch that can administer existing liquid drugs to patients in a rapid manner (< 15 s). Rear-fanged snakes have an intriguing molar with a groove on the surface, which enables rapid infusion of venom into prey based on surface tension and capillary action. The microneedle patch uses snake fang-inspired multiple open grooves for rapid delivery of liquid drugs without a complex pumping system due to capillary action