A self-locking single use syringe comprising a plunger arm, plunger tip, syringe body, and locking sleeve is disclosed. The locking sleeve surrounds tip retaining arms of the plunger arm allowing the tip retaining arms to grasp the plunger tip. When the plunger arm is pulled backwards, sleeve flanges of the locking sleeve protrude into a sleeve lock of the syringe body and the locking sleeve is prevented from moving in a forward direction. As the plunger arm is pushed forward, the tip retaining arms are no longer surrounded by the locking sleeve and the tip retaining arms move outwards and release the plunger tip. After the plunger tip has been released from the plunger arm, the plunger tip and the plunger arm cannot be reconnected and the self-locking single use syringe cannot be reused.
