An inserter for an intrauterine system includes a handle. The handle has a longitudinal opening at its first end, the opening having a longitudinal axis parallel to the longitudinal axis of the inserter, a first end and a second end, a movable slider arranged in the longitudinal opening and having a first end and a second end. The inserter also includes a movable plunger and an insertion tube arranged around the plunger having a first end and a second end, with its second end attached to the slider. The handle further includes a lock for reversibly locking the intrauterine system in relation to the plunger via a removal string of the intrauterine system, the lock being attached to the plunger and being controllable at least by a part or an extension of the slider and/or of the insertion tube or of the handle.