Hormonal birth control (The Basics) - Millennium Pregnancy and Gynecology

What is hormonal birth control? — Hormonal birth control is any pill, injection, device, or treatment that uses hormones to prevent pregnancy in women. There are a few different kinds of hormonal birth control. Some contain the hormones estrogen and progestin. Others contain only progestin.

All hormonal birth control methods are very effective. The methods differ in how easy they are to use and their side effects (table 1):

Pills – Women who take birth control pills need to take a pill every day. Skipping pills can increase the chance of getting pregnant. Birth control pill packets usually include 4 to 7 days of hormone-free pills each month. It is during these hormone-free days that women get their period. Women who prefer not to get a period can skip the hormone-free pills and take a hormone pill every day instead. This is called continuous dosing. It can be done with the patch and the vaginal ring as well. Most birth control pills contain estrogen and progestin but there is one that contains only progestin.
Skin patches – Women can wear a hormone patch on their upper arm, shoulder, back, or hip (picture 1). The patch must be changed once a week. Normally women wear a new patch each week for 3 weeks and then leave the patch off during week 4. Week 4 is when women have their period. Skin patches for contraception contain both estrogen and progestin.
Vaginal rings – A woman can put a bendable ring in her vagina that can stay in place for 3 weeks at a time (picture 2). This ring releases hormones in the vagina. It does not need to be removed when the woman has sex but can be removed for up to 3 hours. Normally women use the ring for 3 weeks and then go without a ring during week 4. Week 4 is when women have their period. Vaginal rings for contraception contain both estrogen and progestin.
Injections – Women who use hormone injections get a shot in the arm or butt every 3 months. Injections for birth control contain only progestin. The medicine used in the shot is called Depo-Provera.
Implants – A birth control implant is a tiny rod that releases hormones in the arm. It must be implanted by a doctor and can stay in the arm for up to 3 years. Implants for birth control contain only progestin.
Hormone-releasing IUD – IUD stands for “intrauterine device.” This is a device that is placed inside the uterus to prevent pregnancy. Two IUDs work by releasing hormones into the body. One is called Skyla, and it can stay in place for up to 3 years. The other is called Mirena, and it can stay in place for up to 5 years (picture 3). The hormone-releasing IUDs contain only progestin.

Hormonal birth control is a safe and reliable way to prevent pregnancy for most women. But it does not protect women from infections that spread through sex.

How do I choose the right hormonal birth control for me? — Work with your doctor or nurse to choose the best option for you. As you think about your decision, think about how likely you are to use each method the right way. Can you remember to take a pill every day? Can you remember to change a patch once a week? Long-acting methods (IUD, implant) are the most convenient because they work for 3 to 5 years, depending on the method. The injection, which works for 3 months, is more convenient than the pill, patch, or ring. Also, ask your doctor how the method you are thinking about will affect your period. See the Table for a list of side effects and risks for each of the different forms (table 1).

Is hormonal birth control safe for all women? — No. Some women should not use estrogen-containing hormonal birth control. This includes women who:

Are age 35 or older and smoke cigarettes – These women are at increased risk for heart attacks and strokes.
Are pregnant
Have had blood clots or a stroke in the past
Have had breast cancer
Have irregular or very heavy periods – Women with this problem should have it checked out before starting hormonal birth control.
Have some types of liver disease – Hormonal birth control can make some types of liver disease worse.
Have some types of heart disease
Get the type of migraine headaches that cause vision problems (flashing or zigzag lights)

Women who have high blood pressure can use hormonal birth control, but their blood pressure needs to be followed closely by a doctor.

Many women who can’t take estrogen-containing hormonal birth control can take hormonal birth control that contains only progestin.

What if I take medicines besides birth control? — Some medicines can affect how well hormonal birth control works. These include:

Some medicines used to prevent seizures (called “anticonvulsants”)
Some antibiotics
St. John’s Wort (an herbal medicine for depression)

If you take any of these medicines, talk to your doctor about how to handle birth control. Also, if you already take hormonal birth control, mention it to any doctor or nurse who might be prescribing medicines for you.

What if I forget to use my hormonal birth control? — If you have sex and have forgotten to use your birth control, you can take a “morning after” pill to reduce the risk of pregnancy. Do this as soon as possible after sex.