Taking your birth control pill regularly is important for making sure the pill works. If you recently vomited, your birth control may have gone with it. Whether your protection against pregnancy has been affected depends on a couple of factors. Experts have advice on how to handle this situation. Learn how to prevent a lapse in protection.

Birth Control Basics

Birth control pills are taken daily to prevent pregnancy. There are different brands of birth control pills, but most are a combination of estrogen and progestin. Progestin-only pills are also available. Birth control pills protect against pregnancy by preventing ovulation. The hormones in the pills prevent pregnancy by stopping your egg from being released from your ovaries. The pill also makes cervical mucus thicker, which makes it more difficult for sperm to reach your egg if one is released.

You can pick whatever regimen works best for you. Some pills allow for a regular monthly period that’s similar to what you may have had before you started taking the pill. There are also options that allow for a reduced menstruation schedule, and some that can eliminate menstruation altogether. Doctors call these extended-cycle or continuous regimens.

Birth control pills are up to 99 percent effective when taken correctly. That means taking the pill at the same time every day and following all other instructions provided by your doctor.

You should make an appointment with your doctor if you’re considering starting or switching birth control pills. They can answer any questions you may have, and they can discuss any risks or side effects you may have.

Common Side Effects of Birth Control

According to Fahimeh Sasan, D.O., assistant professor of obstetrics, gynecology, and reproductive science at Icahn School of Medicine at Mount Sinai, most women don’t have side effects with low-dose combined oral contraceptives. This is the type that’s most commonly prescribed by doctors today.

Still, some women may experience side effects from birth control. This is especially true in the weeks after first starting the pill.

Some common side effects include:

  • irregular bleeding, or spotting
  • nausea
  • vomiting
  • breast tenderness

According to Sherry Ross, M.D., OB-GYN and women’s health expert in Los Angeles, these side effects are usually temporary. Most side effects will fade after you’ve been on the pill for two to three months. If they don’t, you may want to ask your doctor about other options.

How likely you are to experience these symptoms depends on how sensitive you are to the synthetic estrogen or progestin in your birth control pill. There are many brands out there, and each brand has slightly different types and doses of these hormones. If you seem to be experiencing side effects that are affecting your quality of life, another type of birth control pill may work better for you.

What Are the Risk Factors?

Sasan estimates that less than 1 percent of women on the pill will experience nausea from it. Instead, she says nausea is most likely due to missing a pill and having to take two or more pills in the same day.

Women new to taking the pill could also be more at risk for nausea. Did you just start taking the pill within the past month or two? If so, your nausea may be related.

If you’re sensitive to other kinds of medication that aren’t related to birth control or you have certain medical conditions, you could be at increased risk of experiencing nausea from your birth control.

Still, you should rule out other options, such as a virus or another illness, before assuming your birth control is causing your vomiting. Though nausea has been known to happen with birth control users, Ross says vomiting is less likely to occur as a result. If you find that vomiting after ingesting birth control is becoming routine, you should schedule an appointment with your doctor.

What to Do If You Vomited While on Birth Control

Whether your vomiting had anything to do with your birth control, you’ll still want to know what to do to ensure it’s working. You should rule out other medical problems first, such as the flu or a virus. If you’re sick, you’ll want to seek appropriate medical care.

If you threw up after more than two hours of taking the pill, it’s likely your body has already absorbed it and there’s little to be concerned about. However, if you threw up less than two hours after taking the pill, you’ll want to take the next active pill in your pack.

If your vomiting is from an illness and you’re unsure if you’ll be able to keep another pill down, wait until the following day and take two active pills. Just try to take the second active pill 12 hours after the first to avoid any unnecessary nausea from taking the pills too close together.

If you’re ill and unable to keep pills down for more than a few days or if taking the pill is causing you to vomit, you should call your doctor to determine your next steps and learn about additional birth control options. Your doctor may advise you to insert the pill vaginally so that it can be absorbed into the body without the risk of further nausea.

You should also use backup contraception, such as condoms, until you start a new birth control pack or get the go-ahead from your doctor that you’re protected.

How to Prevent Future Nausea

If you believe your birth control pill is causing your nausea, try taking the pill with a meal. Taking it at bedtime may also help.

You’ll also want to make sure you’re on the lowest dose of hormones possible if that’s what’s causing your queasiness. Your doctor will be able to help you determine if there are better options for you. They may just recommend another type of birth control.

“You may want to consider using the vaginal ring birth control that bypasses the stomach, avoiding any gastrointestinal upset,” Ross says. “The progesterone-only arm implants or IUDs are also effective alternatives to oral combination birth control when nausea is disrupting your life.”

Because birth control is only effective when taken as instructed, you’ll want to talk to your doctor if nausea is keeping you from being able to follow the necessary steps. There are options, and you might just need to find a better fit for you.

If your vomiting is from an illness, you should rest and focus on recovery. You’ll also want to ensure your backup contraception plan is in place until you’re sure your birth control protection is effective again.

Read more: Nausea and birth control: Why it happens and how to prevent it »