An injectable substance delivery device comprising a pen device body, a cartridge, a plunger, a drive mechanism, and at least one of a lock-out mechanism and a rate-limiting mechanism. The lock-out mechanism is provided through a ratchet engagement between the body and the plunger to restrict plunger movement and to ensure that the required needle puncture depth is realized prior to injection by locking out the injection mechanism from advancing until a specified force is applied to the skin. A rate-limiting mechanism is also provided through a user compressed plunger drive spring to ensure that a specific rate of injection is realized during the injection of a medicament.