Progestogen-only pills and bleeding disturbances.

The progestogen-only pill (POP), minipill, is quite an effective second line contraceptive. Despite this, it is used relatively infrequently except during lactation. The main reason for this is that women on POP often have abnormal bleeding patterns, with an increased frequency of bleeding, lengthened cycles, breakthrough bleeding, spotting and prolonged bleeding. These menstrual disturbances are the most common quoted reason for discontinuation in up to 25% of users.