Side effects of CICs, besides menstrual bleeding changes, are minimal. The most prominent side effects of CICs are menstrual irregularities during the first 3 to 6 months of use. Dysmenorrhea has been reported in 30 to 65% of women. Other side effects include breast tenderness/pain, headache, and libido changes. Some fluid retention can occur, but weight gain is minimal. Local injection site reactions have also been reported in 15 to 35% of women. Effects of CICs on coagulation and fibrinolysis are minimal and are not thought to be clinically relevant. Conversely, combined oral contraceptive pills containing ethinylestradiol have considerable effects on coagulation and fibrinolysis. The differences can be attributed to the lack of the first-pass effect with parenteral administration as well as structural and pharmacological differences between estradiol and ethinylestradiol.
Combined injectable birth control
Injectable birth control
Long-acting reversible contraception
Heat-based contraception
Male contraceptive
Combined hormonal contraception
Extended cycle combined hormonal contraceptive
Intrauterine device