Side effects[ edit ] In women, the most common adverse effects of MPA are acne, changes in menstrual flow, drowsiness, and can cause birth defects if taken by pregnant women.
Other common side effects include breast tendernessincreased facial hair, decreased scalp hair, difficulty falling or remaining asleep, stomach pain, and weight loss or gain. In the first months of use "irregular or unpredictable bleeding or spotting, or, rarely, heavy or continuous bleeding" was reported.
Adverse effects peak at five weeks, and are reduced with lower doses.
Less frequent effects may include thrombosis though it is not clear if this is truly a risk, it cannot be ruled outpainful urinationheadachenauseaand vomiting. When used as a form of androgen deprivation therapy in men, more frequent complaints include reduced libidoimpotencereduced ejaculate volume, and within three days, chemical castration. At extremely high doses used to treat cancer, not for contraception MPA may cause adrenal suppression and may interfere with carbohydrate metabolism, but does not cause diabetes.
The average return to fertility is 9 to 10 months after the last injection, taking longer for overweight or obese women. By 18 months after the last injection, fertility is the same as that in former users of other contraceptive methods.
The study was prematurely terminated when previously unexpected risks were discovered, specifically the finding that though the all-cause mortality was not affected by the hormone therapy, the benefits of menopausal hormone therapy reduced risk of hip fracturecolorectal and endometrial cancer and all other causes of death were perdita di peso dopo aver interrotto il prempro by increased risk of coronary heart diseasebreast cancerstrokes and pulmonary embolism.
In combination with estrogens in general, MPA may increase the risk of cardiovascular diseasewith a stronger association when used by postmenopausal women also taking CEEs. It was because of these unexpected interactions that the Women's Health Initiative study was ended early due to the extra risks of menopausal hormone therapy resulting in a dramatic decrease in both new and renewal prescriptions for hormone therapy.
However, the study population did show a slightly increased risk of breast cancer in recent users DMPA use in the last four years under age 35, similar to that seen with the use of combined oral contraceptive pills.