progestogen-only injectable contraceptive progestogen-only injectable contraceptive progestogen-only injectable contraceptives (poics) are a form of hormonal contraception and progestogen-only contraception that are administered by injection and providing long-lasting birth control. as opposed to combined injectable contraceptives, they contain only a progestogen without an estrogen, and include two progestin preparations: medroxyprogesterone acetate (brand names depo-provera, provera, depo-subq provera 104) – 150 mg (intramuscularly) or 104 mg (subcutaneously) every 3 months norethisterone enanthate (brand names net en, noristerat, norigest, doryxas) – 200 mg (intramuscularly) every 2 months long-acting reversible contraceptives (larc)backgroundtypehormonalfirst use1957pregnancy rates (first year)perfect use?typical use?usagereversibilityyesuser reminders?advantages and disadvantagessti protectionno research progestogens that have been studied for potential use as poics but were never marketed as such include the progesterone derivatives algestone acetophenide (dihydroxyprogesterone acetophenide) (100 mg/month), chlormadinone acetate (250 mg/3 months), hydroxyprogesterone caproate (250–500 mg/month), gestonorone caproate (2.5–200 mg/1–2 months), and oxogestone phenpropionate (50–75 mg/month), and the testosterone derivatives lynestrenol phenylpropionate (25–75 mg/month), levonorgestrel butanoate, levonorgestrel cyclobutylcarboxylate, and levonorgestrel cyclopropylcarboxylate. some of these have been introduced for use in combined injectable contraceptives instead.