Injection devices for drug delivery and related methods of use and manufacture are disclosed. The injection device may include an outer casing, a container disposed in the outer casing, an injection drive mechanism, and an instructional marker disposed on an exterior surface of the outer casing. The container may include an interior chamber for storing a drug, a subcutaneous delivery member, and a stopper movably disposed in the interior chamber. The injection drive mechanism may be configured to move the stopper to expel the drug through an opening in a distal end of the subcutaneous delivery member upon activation. The instructional marker may indicate a tiling direction for tilting the injection device when the subcutaneous delivery member is inserted into a patient so as to inhibit tissue from occluding the opening in the distal end of the subcutaneous delivery member.