ABSTRACT
In the United Kingdom, the only injectable licensed for long-term use is DMPA (depot medroxyprogesterone acetate), the generic abbreviation is used and is given either as Depo-Provera®, 150 mg intramuscularly or Sayana® Press, 104 mg subcutaneously. DMPA 150 mg as Depo-Provera is given every (12 or) 13 weeks, and norethisterone enantate or NET-EN (Noristerat®) 200 mg is given every 8 weeks. After the pre-loaded syringe for the former is well shaken and the ampoule for the latter, which is oily, is pre-warmed, each is given by deep intramuscular injection in the first 5 days of the menstrual cycle. DMPA is one of the most effective among the reversible methods , with a “perfect use” failure rate of 0.2 (2 in 1000) in the first year of use. It functions primarily by causing anovulation, backed by effects on the cervical mucus similar to those of the POP and COC, as backup.
