Described is an autoinjector comprising a spring holder, a guide cylinder releasably coupled to the spring holder, a drive assembly releasably coupled to the spring holder, a drive spring adapted to apply a force on the drive assembly, and a penetration spring adapted to apply a force on the guide cylinder. The guide cylinder is adapted to accommodate a syringe having a plunger. The drive assembly is coupled to the guide cylinder and adapted to engage the plunger.