A medical injector is provided herein having a body; a reservoir containing first and second mixable component; a stopper; a plunger; a spring disposed to advance the plunger; a first releasable retainer for releasably retaining the plunger in a first state against force of the spring; a first trigger for causing the first releasable retainer to release the plunger; a second releasable retainer for releasably retaining the plunger in a second state against force of the spring; and, a second trigger for causing the second releasable retainer to release the plunger. The spring causes the plunger to advance so that the stopper traverses at least a predetermined extent of advancement thereby causing mixing of the first and second mixable components. Advantageously, with the subject invention, a medical injector is provided which allows for autoreconstitution with subsequent dose setting and autoplunger activation being activated by separate triggers.