Because you have to go to a doctor or hospital to get the shots, it's not as quick and simple as taking a pill at home. You'll need to make time for these appointments, and make sure you can get there and back safely -- and like with any injection, you may feel some pain or soreness during or after each shot.
A serious side effect called post-injection delirium sedation syndrome affects less than 1% of people after taking olanzapine pamoate (Zyprexa Relprevv), a long-acting medicine. It can cause dizziness, confusion, and movements you can't control, and it usually happens within an hour of getting a shot. Because of this small risk, you'll need to stay at your doctor's office for at least 3 hours after your shot so doctors can watch you for side effects.