Halachically, Depo-Provera is similar to oral contraceptive pills in its desirability as a method of contraception. However, as a progesterone-only contraceptive method, it is likely to cause irregular spotting. Unlike the progesterone-only pill (the minipill, femulen), which can be stopped if this spotting causes prolonged time in the niddah state, the effect of Depo-Provera remains in the body for months. For this reason, you should think carefully before embarking on this method. You might discuss with your physician the possibility of trying oral progesterone first to see how your body responds, and then, if you are one of those women who do not spot a lot, try the injectable form of progesterone.
Although progestrone-only contraception does not affect the milk supply for most women (unless it is started within the first week or so after childbirth), there are certainly women who report that it does. This is another reason to consider the oral form of progesterone first to see how your body reacts. These hormones have not been shown to affect nursing babies.
Contemporary halachic authorities differ in their rulings regarding the diaphragm. Our site follows the position that the diaphragm is permissible as a contraceptive method, and may even be preferred in some cases, such as when there are untoward side-effects like prolonged staining.