The cons to birth control injections are similar to other methods of hormonal birth control. It doesn’t protect you against STIs and you might experience side effects like headache, mood changes and acne. These symptoms of injection should eventually become less bothersome or go away, but it’s possible they’ll continue as long as you have the injection.
The contraceptive injection can also change your period, and how this happens can be a bit unpredictable. Many women find that their periods become lighter and shorter or stop altogether, but it’s possible yours might become irregular or heavier. It can also take a long time for your period to get back to normal once you stop taking the shot.
Another downside is that you usually have to go to your doctor to get the injection. But even if you do need to make the trip to the doctor’s, it’s only every three months.