If you’re looking for a way to help prevent pregnancy, your doctor may recommend Phexxi as a birth control option.

Phexxi is a prescription drug used to prevent pregnancy in females* who can become pregnant. For this purpose, you use the drug shortly before having vaginal sex. This means that you use it as needed. You don’t have to use it every day.

Note: Phexxi won’t prevent pregnancy if you use it after you have sex.

* In this article, we use the term “female” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

Phexxi basics

Phexxi has three active ingredients: lactic acid, citric acid, and potassium bitartrate. Unlike some other forms of birth control, Phexxi doesn’t contain hormones.

Phexxi comes as a gel in a prefilled applicator, which you use to apply the drug inside your vagina. At this time, it’s only available as a brand-name drug. It’s not available as a generic drug.

Phexxi is a prescription form of birth control, also known as contraception. If you can become pregnant, using Phexxi before vaginal sex may help prevent pregnancy.

Pregnancy can occur after sexual intercourse when sperm comes in contact with an egg.

Unlike some other forms of birth control, Phexxi doesn’t contain hormones. Phexxi works by creating a poor environment for sperm to survive in. It does so by keeping the pH level of the vagina acidic, which decreases the ability of sperm to move. This makes it harder for the sperm to fertilize an egg.

Note: Phexxi won’t prevent pregnancy if you use it after you have sex.

Also, Phexxi doesn’t protect against sexually transmitted infections (STIs), which are infections transmitted through sexual contact. To help prevent STIs, you can use a barrier method of birth control, such as a condom, together with Phexxi.

Find answers below to some commonly asked questions about Phexxi.

How effective is Phexxi at preventing pregnancy? What’s the pregnancy rate with Phexxi?

When used as prescribed, Phexxi is an effective birth control option. According to the manufacturer, Phexxi may be up to 93% effective at preventing pregnancy when used correctly.

But when Phexxi is used incorrectly, the risk of pregnancy increases. One study found Phexxi to be 86.3% effective for preventing pregnancy. This study may have included results from participants who used the medication incorrectly.

Following your doctor’s instructions for using Phexxi may help the drug work more effectively. To learn more, see the “How is Phexxi used?” section below. Your doctor or pharmacist can also advise you on how to use Phexxi.

For more information about the effectiveness of Phexxi, talk with your doctor or pharmacist.

Is Phexxi a spermicide? How does it compare vs. spermicides?

No, Phexxi isn’t a spermicide. A spermicide is usually a gel or cream that contains a chemical to kill sperm. It can also block the cervical opening so that sperm can’t enter the uterus.

Phexxi is a gel that works to keep the pH level of the vagina acidic. An acidic environment decreases the ability of sperm to move. This makes it harder for the sperm to fertilize an egg, which helps to prevent pregnancy.

The chemical in spermicides can cause irritation and other side effects. Phexxi is made of nontoxic ingredients, which may cause less irritation.

To find out more about how Phexxi compares with spermicides, talk with your doctor or pharmacist.

How does Phexxi work?

Phexxi’s mechanism of action (how it works) creates a poor environment for sperm to survive in. Specifically, Phexxi keeps the pH level of the vagina acidic, which decreases the ability of sperm to move. This makes it harder for the sperm to fertilize an egg, helping to prevent pregnancy.

For more information about how Phexxi works, talk with your doctor or pharmacist.

What should I know about Phexxi vs. vaginal contraceptive film (VCF)?

A vaginal contraceptive film (VCF) is a form of birth control that contains spermicide. The film is less messy than other spermicides, which are usually gels or creams.

The VCF dissolves in the vagina before sex, releasing the spermicide to kill sperm. In addition, it turns into a gel that blocks the cervical opening, preventing sperm from entering the uterus.

The chemical that VCFs contain to kill sperm may cause irritation and other side effects. Phexxi is nontoxic, so it may cause fewer side effects.

Both VCFs and Phexxi need to be used shortly before having vaginal sex. Unlike some other forms of birth control, you don’t need to use Phexxi or VCFs daily.

If you have questions about VCFs and how they compare to Phexxi, ask your doctor or pharmacist.

Costs of prescription drugs can vary depending on many factors. These include what your insurance plan covers and which pharmacy you use.

If you have questions about how to pay for your prescription, talk with your doctor or pharmacist. Or visit the Phexxi manufacturer’s website to see if they have support options.

You can also check out this article to learn more about saving money on prescriptions.

Like most drugs, Phexxi may cause mild or serious side effects. The lists below describe some of the more common side effects it may cause. These lists don’t include all possible side effects.

Keep in mind that side effects of a drug can depend on:

  • your age
  • other health conditions you have
  • other medications you take

Your doctor or pharmacist can tell you more about the potential side effects of Phexxi. They can also suggest ways to help reduce side effects.

Mild side effects

Here’s a short list of some of the mild side effects that Phexxi can cause. To learn about other mild side effects, talk with your doctor or pharmacist, or read Phexxi’s prescribing information.

Mild side effects of Phexxi that have been reported include:

* For more information about this side effect, see the “Side effect focus” section below.

Mild side effects of many drugs may go away within a few days to a couple of weeks. But if they become bothersome, talk with your doctor or pharmacist.

Serious side effects

Serious side effects from Phexxi can occur, but they aren’t common. If you have serious side effects from Phexxi, call your doctor right away. But if you think you’re having a medical emergency, you should call 911 or your local emergency number.

Serious side effects of Phexxi that have been reported include:

* For more information about this side effect, see the “Side effect focus” section below.

Side effect focus

Learn more about some of the side effects Phexxi may cause.

Vaginal irritation

Phexxi can cause vaginal irritation, which can result in symptoms such as burning, itching, or discomfort. These symptoms commonly occurred in studies of Phexxi.

If you have irritation that doesn’t go away or occurs with a rash or other symptoms, this may be an allergic reaction. Talk with your doctor about the specific symptoms you’re having so they can determine whether you’re experiencing an allergic reaction.

What might help

If you have vaginal irritation after using Phexxi, talk with your doctor. It’s possible that the irritation may decrease as your body gets used to using Phexxi.

Also talk with your doctor about ways to prevent this side effect.

Infections

Phexxi may cause infections. In studies of the drug, this side effect was commonly reported. Examples of infections Phexxi can cause include:

While using Phexxi, you should watch for symptoms of infection, such as:

What might help

If you think you may have an infection, contact your doctor. They’ll order tests to determine what type of infection you might have.

In some cases, you may need an antibiotic or antifungal medication to treat your infection.

Some treatments for vaginal infections are taken vaginally. You can continue using Phexxi for birth control even if you’re taking another medication vaginally. Be sure to follow the instructions your doctor gives you for treating a vaginal infection.

Painful urination

You may have painful urination when using Phexxi. This was a commonly reported side effect in studies of Phexxi.

What might help

If you notice painful urination after using Phexxi, talk with your doctor. Painful urination can also be a symptom of a UTI. Your doctor may test your urine to be sure that you don’t have an infection.

If you experience painful urination often when using Phexxi, talk with your doctor about ways to decrease this side effect.

Allergic reaction

Some people may have an allergic reaction to Phexxi.

Symptoms of a mild allergic reaction can include:

A more severe allergic reaction is rare but possible. Symptoms of a severe allergic reaction can include swelling under your skin, typically in your eyelids, lips, hands, or feet. They can also include swelling of your tongue, mouth, or throat, which can cause trouble breathing.

Call your doctor right away if you have an allergic reaction to Phexxi. But if you think you’re having a medical emergency, call 911 or your local emergency number.

Below are details about how to use Phexxi. Your doctor will also explain how you should use this medication, as well as how much of it to use and how often. Be sure to follow your doctor’s instructions.

Using Phexxi

Phexxi comes in an applicator pen prefilled with one dose of gel, which you use to apply the drug inside your vagina. You should apply a dose of Phexxi inside your vagina within an hour before having sex. And you should apply another dose of the drug each time you have sex.

When you’re ready to use Phexxi, follow these steps:

  1. Wash your hands.
  2. Remove the applicator from its foil pouch.
  3. Insert the plunger rod into the applicator.
  4. Remove the pink cap from the tip of the applicator.
  5. Insert the applicator into your vagina as far as it can go without causing discomfort.
  6. Push the plunger rod until it stops.
  7. Remove the applicator and dispose of it safely.

For details on how to use Phexxi, see the manufacturer’s instructions for use.

Accessible medication containers and labels

If it’s hard for you to read the label on your prescription, tell your doctor or pharmacist. Certain pharmacies may provide medication labels that:

  • have large print
  • use braille
  • contain a code you can scan with a smartphone to change the text into audio

Your doctor or pharmacist may be able to recommend a pharmacy that offers these options if your current pharmacy doesn’t.

Using Phexxi with other drugs

In some cases, your doctor may recommend that you use Phexxi with certain other kinds of birth control. Examples include latex condoms and vaginal diaphragms. But you should not use Phexxi if you are using a vaginal ring for birth control, such as NuvaRing (etonogestrel and ethinyl estradiol).

You can also use Phexxi together with medications used to treat bacterial or fungal infections, even if you take them vaginally. For example, Phexxi can be used with:

  • miconazole (Oravig, Monistat)
  • metronidazole (Flagyl)
  • tioconazole (Vagistat)

If you’re taking other medications, talk with your doctor to be sure it’s also safe to use Phexxi.

Questions for your doctor

You may have questions about Phexxi and your treatment plan. It’s important to discuss all your concerns with your doctor.

Here are a few tips that might help guide your discussion:

  • Before your appointment, write down questions such as:
    • How will Phexxi affect my body, mood, or lifestyle?
  • Bring someone with you to your appointment if doing so will help you feel more comfortable.
  • If you don’t understand something related to your condition or treatment, ask your doctor to explain it to you.

Remember, your doctor and other healthcare professionals are available to help you. And they want you to get the best care possible. So don’t be afraid to ask questions or offer feedback on your treatment.

Your doctor will recommend the dosage of Phexxi that’s right for you. Below are commonly used dosages, but always take the dosage your doctor prescribes.

Form

Phexxi is available as a vaginal gel. It comes in a prefilled applicator that is ready to use.

Recommended dosage

Phexxi comes in an applicator pen prefilled with one dose of gel, which you use to apply the drug inside your vagina. It doesn’t need to be used daily or regularly to prevent pregnancy. Instead, you’ll apply a dose of the drug within an hour before having sex. And each time that you have sex, you should apply another dose beforehand.

Questions about Phexxi’s dosage

Below are answers to a few questions about Phexxi’s dosage.

  • Will I need to use Phexxi long term? You can use Phexxi long term or short term. If Phexxi works well as a birth control option for you, your doctor may recommend that you use it long term. But if you want to start planning for a pregnancy, you can stop using Phexxi at any time.
  • How long does Phexxi take to work? As soon as you use your dose of Phexxi, the medication begins working to prevent pregnancy.

Before you start using Phexxi, be sure to talk with your doctor about other medications you take or other medical conditions you have. They will be able to help you determine if Phexxi may be a safe birth control option for you.

Interactions

Taking a medication with certain vaccines, foods, and other things can affect how the medication works. These effects are called interactions.

Before taking Phexxi, be sure to tell your doctor about all medications you take, including prescription and over-the-counter types. Also describe any vitamins, herbs, or supplements you use. Your doctor or pharmacist can tell you about any interactions these items may cause with Phexxi.

Interactions with drugs or supplements

At this time, Phexxi isn’t known to interact with other drugs or supplements. But it’s still important to tell your doctor about any other medications that you take before you start using Phexxi. This helps your doctor determine whether Phexxi is safe for you to use.

Warnings

Phexxi may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before you use Phexxi. Factors to consider include those in the list below.

  • Urinary tract problems. If you have any problems with your urinary tract, including bladder or kidney problems, tell your doctor before using Phexxi. Depending on your condition, your doctor may recommend a different form of birth control for you.
  • Allergic reaction. If you’ve had an allergic reaction to Phexxi or any of its ingredients, your doctor will likely not prescribe Phexxi. Ask your doctor what other medications are better options for you.
  • Frequent urinary tract infections (UTIs). If you have UTIs that occur often or keep coming back, Phexxi may not be right for you. This medication may increase your risk of UTIs, which in rare cases can be serious. If you have frequent UTIs, your doctor may recommend a different birth control option for you.

Phexxi and alcohol

There are no known interactions between Phexxi and alcohol. If you would like to drink alcohol while using Phexxi, talk with your doctor about how much alcohol is safe for you to drink.

Pregnancy and breastfeeding

Phexxi is used to prevent pregnancy. So you should not use Phexxi if you’re already pregnant. It’s not known what effects Phexxi may have on a developing fetus.

It’s also not known if Phexxi may be safe to use while breastfeeding or what effects the drug may have on a breastfeeding child. If you’re breastfeeding, talk with your doctor before using Phexxi.

Do not take more Phexxi than your doctor prescribes. Using more than this can lead to serious side effects.

What to do in case you take too much Phexxi

Call your doctor if you think you’ve taken too much Phexxi. You can also call 800-222-1222 to reach the American Association of Poison Control Centers or use its online resource. However, if you have severe symptoms, immediately call 911 or your local emergency number. Or go to the nearest emergency room.

If you’re interested in learning more about Phexxi, talk with your doctor. Asking questions can help you decide whether Phexxi might be a good birth control option for you. Here are a few to help you get started:

  • Will my other forms of birth control increase my risk of side effects from Phexxi?
  • What should I do if I become pregnant while using Phexxi?
  • What should I expect from using Phexxi?
  • How can I prevent side effects that I experience from Phexxi?

If you would like to learn more about other types of birth control, see this article. For more facts, questions, and information on birth control, see the Healthline birth control hub.

Q:

Do I need to start using Phexxi at a specific point in my menstrual cycle?

Anonymous

A:

You can use Phexxi at any time during your menstrual cycle, including the days of your period.

After a birth, abortion, or pregnancy loss, talk with your doctor about when it’s safe to have vaginal sex again. You can start or resume using Phexxi at that time.

Damilola Omopariola, PharmD, BCACPAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.