What Is It?

The birth control ring is a soft, flexible, doughnut-shaped ring about 2 inches (5 centimeters) in diameter. It is inserted into the vagina, where it slowly releases hormones — the chemicals the body makes to control organ function — through the vaginal wall into the bloodstream. The hormones in the ring affect the ovaries and the uterus in order to prevent pregnancy.

How Does It Work?

The combination of the hormones progesterone and estrogen in the birth control ring prevent ovulation (the release of an egg from the ovaries during a girl's monthly cycle). If an egg isn't released, a girl can't get pregnant because there's no egg for a guy's sperm to fertilize.

The hormones in the ring also thicken the cervical mucus, making it difficult for sperm to enter the uterus and reach any eggs that may have been released. The hormones in the ring can also sometimes affect the lining of the uterus so that an egg will have a hard time attaching to the wall of the uterus.

Like the birth control pill or the patch, a girl uses the birth control ring based on her monthly menstrual cycle. She inserts it into the vagina (similar to the insertion of a tampon) on the first day of her menstrual cycle or before day 5 of her menstrual cycle. It remains in place for 3 weeks in a row. At the end of the third week, on the same day of the week it was inserted, about the same time of day, she removes it. Within a few days, her menstrual period should start. At the end of the fourth week, on the same day of the week the last ring was inserted, she inserts a new ring and the process begins again. The new ring should be placed on that day, even if a girl still has her period.

Because the hormones in the ring don't take effect immediately, another form of birth control (such as a condom) should be used for 7 days when a girl first starts using the ring. After 7 days, the ring should work alone to prevent pregnancy. But continuing to use condoms will protect against sexually transmitted diseases (STDs).

The exact position of the ring in the vagina is not critical as long as it feels comfortable. This is because the ring does not work as a barrier method of birth control. If it doesn't feel comfortable, a girl can push it further back or remove and reinsert it. Most girls do not feel the ring once it is in place. It can be left in place during swimming, bathing, and exercise. It can also remain in place during intercourse.

The ring is held in place by the vaginal muscles, so it's unlikely that it will fall out. If it does, it can be rinsed under cool water (not hot!) and reinserted within 3 hours. If more than 3 hours pass without the ring in the vagina, there's a chance a girl can become pregnant and she'll need to use an additional form of birth control until the ring has been in place for 7 days. If the ring is out for more than 3 hours during your third week wearing it, call your doctor to see what to do. He or she may have you put a new ring in, or tell you not to replace it, so you get your period early. Either way, an additional form of birth control should be used.

How Well Does It Work?

The effectiveness of the vaginal ring seems to be similar to other hormonal methods of birth control, like the patch or the Pill. Results show that over the course of 1 year, about 8 out of 100 typical couples who rely on the ring to prevent pregnancy will have an accidental pregnancy. Of course, the chance of getting pregnant depends on whether a girl uses the ring correctly. Delaying or missing a monthly insertion or removing a ring too early reduces its effectiveness.

In general, how well each type of birth control method works depends on a lot of things. These include whether a person has any health conditions or is taking any medications that might interfere with its use. It's important for a doctor to be aware of all medications and herbal supplements that a girl might be taking. Although using the ring means a girl does not have to remember to take a pill every day or replace a patch, it still needs to be removed after 3 weeks and then replaced a week later. If it is not replaced on time, the ring loses its effectiveness.

Protection Against STDs

The vaginal ring does not protect against STDs. Couples having sex must always use condoms along with the vaginal ring to protect against STDs.

Abstinence (not having sex) is the only method that always prevents pregnancy and STDs.

Possible Side Effects

The vaginal ring is a safe and effective method of birth control. Most young women who use the ring have no side effects. Smoking cigarettes and using the ring can increase a girl's risk of certain side effects, which is why health professionals advise girls who use the ring not to smoke.

The side effects that some women have while using the ring are similar to those experienced with the birth control pill. These may include:

• irregular menstrual bleeding
• nausea, headaches, dizziness, and breast tenderness
• mood changes
• blood clots (rare in women under 35 who do not smoke)

Other possible side effects seen in ring users include:

• vaginal irritation or infections
• vaginal discharge
• problems with contact lens use, such as a change in vision or inability to wear the lenses

Many of these side effects are mild and tend to disappear after 2 or 3 months.

Who Uses It?

The vaginal ring may be a good choice for young women who find it difficult to remember to take a pill every day or who have difficulty swallowing pills. They must feel comfortable enough with their bodies to be able to insert a device into the vagina.

Not all women can — or should — use the vaginal ring. In some cases, medical or other conditions make the use of the ring less effective or more risky. For example, it is not recommended for women who have had blood clots, severe high blood pressure, certain types of cancers, certain types of migraine headaches, or diabetes with certain complications.

Girls who have had unexplained vaginal bleeding (bleeding that is not during their periods) or who suspect they may be pregnant should talk to their doctors, stop using the ring, and use another form of birth control in the meantime.

Girls who are interested in learning more about the possible health benefits and risks of different types of birth control, including the ring, should talk to a doctor or other health professional.

How Do You Get It?

A doctor or a nurse practitioner must prescribe the ring. He or she will ask questions about health and family medical history, then do a complete physical exam, which may include a blood pressure measurement and a pelvic exam. If recommending the ring, the doctor or nurse practitioner will write a prescription and provide instructions on how to use it.

Girls who start using the ring may be asked to return within a few months for a blood pressure measurement and to ensure that there are no problems. After that, a doctor may recommend routine exams once or twice a year or as needed.

How Much Does It Cost?

The ring usually costs between $30 and $50 a month, although health and family planning clinics (such as Planned Parenthood) might sell them for less. In addition, the vaginal ring and doctor's visits are covered by many health insurance plans.

Reviewed by: Larissa Hirsch, MD
Date reviewed: September 2009