What are the side effects of the contraceptive injection?

What are the side effects of the contraceptive injection?

Like any other medicine, the contraceptive injection can have side effects. These are usually minor and may go away after a few days, although in some cases they may last for 13 weeks, which is how long the injection remains in your body.
 
Side effects may incude:
  1. headaches
  2. acne and other skin eruptions
  3. decreased sex drive
  4. mood swings