The birth control pill is one of the most popular forms of prescription contraception. When many people think of “the pill” they are thinking of the combination birth control pill; however, there are two different types of birth control pills that can be prescribed to women to prevent pregnancy. The traditional birth control pill contains an estrogen and a progestin (a synthetic form of the body’s progesterone hormone) while the “mini-pill” contains only progestin. While both are pills that prevent pregnancy, they are not interchangeable. They work in different ways and carry different risks and benefits.
The combination birth control pill primarily functions by preventing a woman from ovulating or producing an egg. When a woman does not ovulate, the egg is not released, and she cannot become pregnant. This medication also makes the cervical mucus thicker, making it more difficult for sperm to enter the uterus, and keeps the lining of the uterus thin.
The combination birth control has many benefits, and it may be prescribed for other medical conditions because of these effects. It can make periods lighter and more regular and reduce cramping during a woman’s cycle. It can also reduce acne symptoms and reduce facial hair growth. Studies have shown that women who had been on the combination birth control pill had lower rates of ovarian, uterine, and colon cancer.
The combination birth control pill is a safe medication used by millions of women; however, risks include a small increased risk of deep venous thrombosis (DVT), heart attack, and stroke. Women with certain health conditions should not be prescribed the combination birth control pill because of this risk. For example, women with high blood pressure, multiple risk factors for cardiovascular disease, or history of DVT, heart attack, or stroke should not take the combination birth control pill due to this elevated risk.
The progestin-only pill, or mini-pill, works differently from the combination pill in how it prevents pregnancy. Its main mechanism of action is thickening cervical mucus and thinning the lining of the uterus. It can suppress ovulation, but not in all women and not always completely; however, it is still an effective birth control method through its other mechanisms. Like the combination pill, the mini-pill can reduce heavy bleeding for women. Many women have lighter bleeding on the mini-pill, but they can also have irregular periods with this medication.
The mini-pill does not carry any increased risk of DVT, heart attack, or stroke. Women who should not take the combination birth control pill can often take the mini-pill safely. The mini-pill is also often prescribed for women who are breastfeeding as the estrogen component in the combination pill can sometimes affect milk supply.
The combination pill and the mini-pill have approximately the same rate of efficacy in studies. With typical use, 9 out of 100 women on the combination pill or the mini-pill will become pregnant in one year of use. With perfect use, the chance of a woman becoming pregnant is closer to 1 in 100, with use of either pill. It is important for both the combination pill and the mini-pill to be taken every day, without missing doses and with taking the pill at the same time every day. However, the mini-pill containing norethindrone is known to be processed more quickly in the body, which means that if the dose of the mini-pill is late by even 3 hours, it is considered a “missed dose” of the medication. If this happens, a woman should use an alternate form of contraception or abstain from intercourse in order to reduce the risk of unintended pregnancy.
With so many birth control options available, it is important to have a conversation with your healthcare provider to see which option would work best for you, based on your personal preferences and your medical history.