How the Birth Control Pill Works

Extended-cycle Birth Control Pill

The newest type of pill is especially designed for continuous use. Sometimes known as the extended-cycle pill, it either reduces the number of periods a woman has or eliminates them completely. The three brands currently on the market are:

  • Lybrel - 365 days of pills, resulting in no periods at all
  • Seasonale - 84 days of pills, 7 days of inactive pills, resulting in a period four times a year
  • Seasonique - 84 days of active pills, 7 days of lower-dose estrogen-only pills, resulting in a period four times a year

A health care provider might prescribe extended-cycle pills for a woman who has painful periods even on typical combination pills, or for someone who just wants to avoid the inconvenience of a monthly period.

Extended-cycle pills can be more effective than combination pills and better at treating some disorders like chronic benign cysts, endometriosis and PMDD. These types of pills carry the same side effects as combination pills but are more likely to cause spotting. They may also cause concern among fertile women because there are fewer periods, or none at all, to serve as an indication that they're not pregnant.

Although it may seem unhealthy to limit or go completely without a period, it isn't. The constant levels of estrogen and progestin keep the uterine lining very thin, so there isn't really anything to shed anyway. For the whole story, read Do you really need a period every month?

The pill generally costs between $20 and $50 per month. Most insurance plans cover the pill, and older brands and generics are usually less expensive. The extended-cycle pills cost more because more pills are taken per month. Family planning clinics and local health departments often distribute a pill supply for six months or longer at a reduced rate.