The last week of birth control pills usually consists of inactive pills, which do not contain any hormones. They are sometimes called placebo pills or sugar pills.
Different types and brands of the pill may include various amounts of placebo pills in their packs. Common types of combination pill packs include:
- 28-day pill packs: For most brands, the pills for the first 3 weeks of the pack contain the hormones, while those for the last 7 days do not contain any hormones at all. These pills are known as placebo pills, and they are there to help people make a habit of taking the pill regularly. Some newer pill brands use fewer placebo pills.
- 21-day pill packs: These pill packs contain 21 days of pills with active hormones. A person will then wait 7 days before starting a new pack, during which time they will not take any placebo pills.
- 91-day pill packs: Some types of pill contain 84 active pills and 7 inactive pills. People taking these pills should only get their period once every 3 months.
The placebo pills are there to mimic the natural menstrual cycle, but there is no real medical need for them.
People usually get their period while taking the placebo pills because the body reacts to the drop in hormone levels by shedding the uterine lining.
People do not need to take the placebo pills if they would prefer to take a break instead. The birth control pills for the last week do not contain any active hormones.
However, people who decide to skip the placebo pills must remember to restart the next pill pack on time. They need to skip no more than 7 days of pills to continue to prevent pregnancy.
It can be helpful to mark the date on a calendar or to set an alert on a computer or cell phone as a reminder.
To reduce the risk of an unplanned pregnancy, anyone who is unsure which pills are active and which are inactive should speak to a doctor or pharmacist.
Some people elect to skip the placebo pills and restart the next pack right away, without a break in hormones. This may prevent a period from occurring.
Many people use this technique for convenience, for example, to keep them from getting their period while on vacation or in anticipation of a significant event.
It is safe for most people to do this occasionally, but it is best to speak with a doctor first.
A doctor can provide guidance regarding the safety of skipping the placebo pills, as well as how often a person should have their period.
Some varieties of birth control pill will not allow back-to-back dosing, as the dosing varies by week within the pack. Therefore, people should ensure that the pill they are taking is suitable to use on an extended cycle.
If a person is skipping the placebo pills due to a medical issue, such as endometriosis or polycystic ovary syndrome (PCOS), a doctor can recommend birth control pills that provide continuous hormones.
Many women find that they skip a period or experience lighter bleeding while taking birth control pills, especially over time.
This may be due to a few vital functions of the pill, which works by:
- stopping ovulation
- thickening cervical mucus to block sperm
- keeping the lining of the uterus thin to prevent implantation
When the uterine lining is thin, there will be less blood and tissue to shed during the hormone-free period.
While it can be alarming to miss a period while taking the pill, it is common and can be completely normal.
If a person is concerned that they may be pregnant, they can take a home pregnancy test or see a doctor.
In packs of combination birth control pills, the placebo pills are usually sugar pills. People do not need to take them to make the birth control pills effective, but it may be helpful to keep to a daily routine of taking the pill.
While people do not need to take the placebo pills each month, they should speak to their doctor before manipulating their pills to skip their periods.
With typical use, birth control pills are 91 percent effective at preventing pregnancy, regardless of whether or not people take the placebo pills.
It is best to consult a doctor or pharmacist with any questions or concerns about taking the pill or distinguishing between the active and inactive pills.