For some women, having a period every month is little more than an inconvenience. For others, it can mean a week of pain and discomfort. Between 20% and 40% of women have unpleasant periods.﻿﻿ Treating symptoms like headaches, painful cramping, heavy bleeding, and PMS with drugs and heating pads is one way to deal with them. Another way may be to avoid them altogether by taking birth control pills.

How Oral Contraceptives Work

When birth control pills were introduced in the 1950s, they were marketed in packages of 30 pills—21 of these contained hormones that put a halt to the natural buildup of tissue and blood in the uterine lining in preparation for conception.﻿﻿ The other seven were placebos that allowed for a week-long period. This 21/7 regimen was devised because it most closely mimicked a natural menstrual cycle.﻿﻿

By having a period once a month women would be less likely to worry that birth control pills would interfere with their “normal” periods and therefore would be more likely to use them.﻿﻿ Having a monthly period also assured women the birth control pill was doing its job—preventing pregnancy. Remember, there were no home pregnancy tests back then.

The bleeding you experience while on birth control pills isn't menstrual bleeding, which is the shedding of the blood and tissue that accumulates in the uterine lining in preparation for pregnancy. If after ovulation there's no fertilized egg to embed in the uterus, the thickened lining is sloughed off. The false period that takes place while on oral contraceptives is called withdrawal bleeding.﻿﻿ The blood does come from the uterus, but because the lining has remained thin, the bleeding is light.

The Safety of Continuous Contraceptives

There's no danger in preventing the thickening of the uterine lining by taking 21/7 birth control pills. Nor is there any danger in taking hormones for more than 21 days in order to put off withdrawal bleeding. A 2004 study even found that eliminating withdrawal bleeding through extended or continuous use of oral contraceptives may have health or lifestyle benefits.﻿﻿

In fact, for decades doctors have been prescribing birth control pills to manipulate the monthly cycles of women for a variety of reasons: to help manage menstrual-related health disorders or severe period-related symptoms; to make it easier to handle physically demanding jobs; and even to make sure a woman won't have her period while on vacation or during her honeymoon.﻿﻿

Is there a limit to how long a woman can go without a period? At least 84 days, according to research in women under 40.﻿﻿ One study found that when taken daily for 84 days followed by 7 days of placebo—which lowers the number of periods per year from 13 to four—extended cycle pills were as effective in preventing pregnancy and just as safe as the typical 21/7 regimen. Another study looking at a specific extended-cycle birth control pill, Seasonale (ethinyl estradiol and levonorgestrel), found that the negative side effects of this medication are typical of all birth control pills, with the exception of breakthrough bleeding, which was more common with Seasonale.﻿﻿

If you have monthly periods that cause symptoms so severe you aren't able to participate in activities you enjoy, an extended-cycle birth control pill may be a simple and safe way to deal with them.﻿﻿ Talk to your gynecologist or regular practitioner. You could be just one daily pill away from eliminating painful, disruptive periods.