This is unpredictable and may result in erratic or prolonged bleeding or nuisance spotting. Amenorrhoea develops in half the women given DMPA within 12 months of starting use. Women using DMPA usually have a delay in the return of their fertility after treatment. Counselling before starting progestogen-only methods is essential in helping women accept the menstrual irregularity. Progestogen-only methods are contraindicated in suspected pregnancy, breast cancer and undiagnosed vaginal bleeding.
Relative contraindications are active viral hepatitis and severe chronic liver disease.
There are oral, subcutaneous, intramuscular, intrauterine and intravaginal routes of administration. At present, only the oral and intramuscular preparations are available in Australia. The mini-pill contains between one third and one fifth of the dose of progestogen used in the combined pill. Two formulations are available in Australia, one containing levonorgestrel 30 micrograms, the other norethisterone 350 micrograms. The mini-pill is slightly less effective than the combined pill as its major effect relies on changes in the cervical mucus.