Hi, SP, I haven't used Depo, but have many patients that do. Irregular bleeding/spotting is the most common side effect. Usually goes away by 4 injections, if you can stand it until then. A way of trying to stop it is to take ibuprofen 800mg three times a day for 5 days. That's 4 over-the-counter 200 mg Motrin or Advil at a time. With food, so it doesn't hurt your stomach. Another solution is to get the next injection 10 weeks after the first one, rather than waiting the 12 weeks. Good luck with it.