Depot contraceptives can achieve a high level of efficacy independent of the problems associated with patient compliance. They are particularly suitable for patients requiring long term contraception, and for short-term contraception in women immunised against rubella or whose partners have recently had a vasectomy. They are designed to release a progestogen over a prolonged period ranging from eight weeks to five years depending on the device and formulation. Contraceptive efficacy is dependent on the progestogen.
There are two main types of depot contraceptive:
Intramuscular/subcutaneous Depo-Provera (medroxyprogesterone) and Noristerat (norethisterone) are administered by deep im injection and provide contraceptive cover for three months and eight weeks, respectively. Sayana Press is a subcutaneously injected formulation of medroxyprogesterone that provides 13 weeks' cover. Patients should be counselled as to the long-term action and potential side effects of these contraceptives and warned that it is not possible to reverse their effects immediately.
Subdermal Nexplanon consists of a single etonogestrel-releasing rod that is implanted subdermally. The rod should be withdrawn or replaced every three years.