The Depo-Provera shot is an injectable contraception that only requires one shot every three months. It contains Progesterone which effectively inhibits ovulation. You must get your shot every 3 months or it will not be effective. A back-up form of contraception should be used for the first week after the first injection or if a woman is late or misses an injection. Women may experience unpredictable spotting for 6-8 months after the first injection and eventually may not have a cycle at all. A lack of periods is normal on Depo-Provera and can be a benefit many women enjoy. Some women experience an increase in depression and should notify their provider if this occurs. The Depo-Provera shot itself will not cause weight gain, but it will increase a woman’s appetite in which case she may gain weight. Long-term use of Depo-Provera may cause decreased bone density and smoking increases this risk as well. It is helpful to participate in weight-bearing exercises, take a calcium supplement and quit smoking to counteract this effect. Depo-Provera may decrease seizure activity but anti-seizure medications do not change its effectiveness. It is safe to use during breastfeeding. It may take up to 12 months to return to fertility once the shot is discontinued