A safety syringe (100； 700； 1200) comprising: a barrel (104； 704； 1204) having an opening at an end thereof； a syringe plunger (108； 708； 1208) configured to move within the barrel such that an inward stroke of the syringe plunger causes a substance within the barrel to be expelled from the opening； and a sheath (112； 712； 1212) configured to cover at least partially the opening in the barrel after use of the syringe, wherein the safety plunger is decoupled from the sheath and is configured to couple to the sheath at a first point on the inward stroke and to decouple from the syringe plunger at a second point on the inward stroke such that the sheath is moveable independently of the syringe plunger and further movement of the sheath after decoupling at least partially covers the opening in the barrel.
