Injectable contraceptives

Injectable contraceptives are artificial hormonal preparations administered by a deep intramuscular injection into the muscle of the arm or buttock, to be effective immediately. From the injection site they are slowly absorbed into the bloodstream and the body gets sufficient levels of hormone to provide contraception for one to three months, depending on the type of injectable contraceptive used. Injectable contraceptives can consist of progesterone-only preparations, or combined oestrogen and progesterone preparations (Figure 6.1).