In Star Trek, a hypospray is the medical device that injects drugs without using a needle.
The hypospray is a handheld instrument used throughout Star Trek to administer medicines, vaccines, and anesthetics. It uses a pressurized, extremely fine stream to deliver medication through the skin, avoiding a conventional needle and syringe.
The device appears in Star Trek: The Original Series and became a standard part of Federation medical equipment in later series. Doctors and nurses commonly use it in sickbays, although different episodes show varying designs and operating details.
A hypospray is often confused with a tricorder. A tricorder is primarily a scanning and diagnostic instrument, while a hypospray delivers treatment. Star Trek's fictional device resembles real needle-free jet injectors, which have been developed for vaccinations and other medical applications.