Nexplanon is a prescription drug used to help prevent pregnancy. Nexplanon can cause mild to severe side effects, such as weight gain, nausea, and changes in period bleeding.

Nexplanon is used to help prevent pregnancy in females* of any age who can become pregnant.

The active ingredient in Nexplanon is etonogestrel. (An active ingredient is what makes a drug work.) The drug comes as an implant that’s inserted under the skin of your arm by a healthcare professional.

Keep reading to learn about the common, mild, and serious side effects that the Nexplanon implant can cause. For a general overview of the drug, including details about its uses, see this article.

* 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.

Some people may experience mild to serious side effects during their Nexplanon treatment. Examples of Nexplanon’s commonly reported side effects include:

* To learn more about this side effect, see the “Side effects explained” section below.

Nexplanon may cause mild side effects in some people. Examples of mild side effects that have been reported include:

* To learn more about this side effect, see the “Side effects explained” section below.
† To learn more, see the “Does Nexplanon cause weight gain?” section below.

Other side effects of Nexplanon are specific to having the implant inserted or removed. To learn more, see the “Side effects of Nexplanon insertion and removal” section below.

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist.

Nexplanon may cause mild side effects other than the ones listed above. See the Nexplanon prescribing information for details.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Nexplanon, visit MedWatch.

Although uncommon, it’s possible to have serious side effects with Nexplanon. Serious side effects that have been reported with Nexplanon include:

Other side effects of Nexplanon are specific to having the implant inserted or removed. To learn more, see the “Side effects of Nexplanon insertion and removal” section below.

If you develop serious side effects with Nexplanon, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

* To learn more about this side effect, see the “Side effects explained” section below.

It’s possible for Nexplanon to cause weight gain. In fact, weight gain was a common side effect reported in studies of Nexplanon.

In studies, people with Nexplanon gained an average of 2.8 pounds (lb) in 1 year and 3.7 lb in 2 years. But it’s not known how much of the weight gain was due to Nexplanon. Some people in studies had the Nexplanon implant removed due to weight gain.

If you experience weight gain with Nexplanon, you may lose some or all of the weight you gained once the implant is removed.

If you’re concerned about weight gain from Nexplanon, talk with your doctor. They may be able to recommend ways to help manage your weight.

Nexplanon is implanted under the skin of your arm. You may experience side effects after your doctor inserts or removes the Nexplanon implant.

Possible side effects from having Nexplanon inserted or removed include:

  • scarring
  • pain or itching at the site where Nexplanon is inserted
  • cramps
  • numbness
  • bleeding or bruising where Nexplanon is inserted
  • infection
  • thickening of your skin where the implant is inserted
  • abscess (swollen bump containing pus)

In studies of Nexplanon, side effects after the implant was inserted or removed weren’t common. But if you have any side effects after getting Nexplanon inserted or removed, talk with your doctor. They can determine the best ways to treat these side effects.

In rare cases, the Nexplanon implant may move within your arm from the site it was inserted. When the implant moves deeper into your arm, it can cause serious symptoms, such as:

In very rare cases, it’s possible for the implant to enter the bloodstream and travel to other areas of the body, such as the chest or lungs. This can cause serious symptoms, such as:

If you experience any of these symptoms, call your doctor right away or go to the nearest hospital.

Get answers to some frequently asked questions about Nexplanon’s side effects.

Is it possible to have spotting or other side effects 1 to 2 years after Nexplanon is inserted?

Yes, Nexplanon may cause long-term changes in your period bleeding. So it’s possible to have spotting or other side effects of Nexplanon 1 to 2 years after it’s been inserted.

In studies, during the first 2 years of having Nexplanon, some people had more frequent or longer periods, while others had their periods stop completely.

In most cases, any changes to period bleeding will occur in the first 3 months after having Nexplanon inserted. These changes may continue as long as you have the Nexplanon implant.

Talk with your doctor about what you should expect with Nexplanon. Also, talk with them if you have any changes in your period that seem unusual during treatment with Nexplanon.

To learn more about spotting or other changes in period bleeding, see the “Side effects explained” section below.

Will I have bruising or itchiness when Nexplanon is inserted or removed?

It’s possible that you may experience bruising or itching when your Nexplanon implant is inserted or removed. Although they weren’t common, these side effects were reported in people who had Nexplanon inserted or removed in studies.

Bruising or itchiness can occur because Nexplanon is inserted under your skin.

For more information about side effects you could have when Nexplanon is inserted or removed, see the “Side effects of Nexplanon insertion and removal” section above.

Does Nexplanon cause brown spotting?

Yes, Nexplanon can cause spotting, which may include brown spotting. (With spotting, you have light bleeding that happens outside of your regular period.) Nexplanon can change your period bleeding patterns. In some people, this may cause heavier periods, irregular bleeding, or spotting.

Spotting is a common side effect of Nexplanon, but you should still tell your doctor if you experience it. In some cases, spotting may be a sign of another condition, such as pregnancy, or in rare cases, cancer. Your doctor can check that the spotting you’re experiencing is from Nexplanon and not another cause.

Does Nexplanon cause low libido (low sex drive)?

It’s possible that Nexplanon may cause low libido. This wasn’t a side effect reported in studies of Nexplanon. But after Nexplanon became available for use, some people who got the implant reported having low libido.

If you’re concerned about low libido during your Nexplanon treatment, talk with your doctor. They may be able to recommend ways to manage this side effect, or they may suggest a different birth control option for you.

Are cramps a side effect of Nexplanon?

Yes, Nexplanon can cause cramps or belly pain. In studies, belly pain was one of the most common side effects that people with Nexplanon reported.

If you experience mild cramps or belly pain while you have Nexplanon, talk with your doctor. They can determine what may be causing your cramps. In some cases, they may recommend using a medication such as acetaminophen/caffeine/pyrilamine (Midol) to treat your cramps.

If you experience belly pain or cramping that’s severe, tell your doctor right away or go to the nearest hospital. In some cases, serious belly pain or cramping can be a sign of an ectopic pregnancy. (With an ectopic pregnancy, a fertilized egg attaches to an area other than the uterus, such as the fallopian tube.)

If not treated, ectopic pregnancies can cause serious complications or could even be fatal. If you think you may be pregnant while you have a Nexplanon implant, talk with your doctor right away.

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

Spotting or other changes in period bleeding

Nexplanon may cause changes in your period bleeding, including spotting (light bleeding that happens outside of your regular period). In fact, changes in bleeding were a common side effect that people with Nexplanon reported in studies. This was also the most common reason that people had their Nexplanon implant removed early.

Nexplanon may cause:

  • more or less frequent bleeding during your period
  • breakthrough bleeding or spotting
  • changes in the heaviness of your bleeding
  • changes in how long your period lasts
  • irregular bleeding

In some cases, you may have no period during treatment with Nexplanon.

In most cases, any changes to period bleeding will occur in the first 3 months after having Nexplanon inserted. These changes may continue as long as you have Nexplanon.

What might help

Before having your Nexplanon implant inserted, talk with your doctor about what changes in bleeding you may experience.

Spotting and other changes in bleeding are common with Nexplanon, but you should still tell your doctor if you experience these side effects. In some cases, they may be a sign of a different condition, such as pregnancy, or in rare cases, cancer. Your doctor can check that the side effects you’re experiencing are from Nexplanon and not another cause.

If changes in bleeding or spotting from Nexplanon are bothersome to you, your doctor may recommend a different birth control option.

Changes in mood (“mood swings”)

It’s possible to have changes in mood with Nexplanon. Nexplanon is hormonal birth control, so it changes your hormone levels to help prevent pregnancy. These hormone changes may cause changes in mood (sometimes called “mood swings”). This may include depression. Symptoms of mood changes or depression may include:

  • feeling sad or hopeless
  • feeling irritable
  • sleeping more or less often than usual
  • weight gain or weight loss
  • losing interest in things you used to enjoy

What might help

If you experience depression or other changes in mood with Nexplanon, tell your doctor. In some cases, they may be able to prescribe other medications, such as antidepressants, to manage your mood changes. But if you have severe mood changes or depression, your doctor may recommend having your Nexplanon implant removed and trying a different birth control option.

Breast pain

Nexplanon may cause breast pain in some people. Breast pain was a common side effect that people with Nexplanon reported in studies.

It’s also possible for Nexplanon to cause other breast-related side effects. Although these side effects weren’t reported in studies, they’ve been reported by people who got Nexplanon after it was approved for use. Other breast-related side effects that people with Nexplanon reported after it was approved include:

  • breast discharge
  • breast growth

What might help

If you have breast pain with Nexplanon, talk with your doctor. In some cases, they may be able to recommend using other medications, such as acetaminophen (Tylenol), to help ease the pain.

If you experience any other breast-related side effects, tell your doctor. They can determine whether Nexplanon may be causing your side effects and the best ways to treat them.

Nausea

Nexplanon may cause nausea, but this wasn’t a common side effect reported in studies of the drug.

What might help

If you experience nausea with Nexplanon, talk with your doctor. They can determine whether Nexplanon may be the cause. They can also suggest the best ways to treat your nausea.

Allergic reaction

Like most drugs, Nexplanon can cause an allergic reaction in some people.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, discoloration, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. They may suggest a treatment to manage your symptoms. Examples include:

  • an over-the-counter antihistamine that you swallow, such as Benadryl (diphenhydramine)
  • a product you apply to your skin, such as hydrocortisone cream

If your doctor confirms you’ve had a mild allergic reaction to Nexplanon, they’ll decide whether you should continue your treatment.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you’ve had a serious allergic reaction to Nexplanon, they may have you switch to a different treatment.

Keeping track of side effects

Consider taking notes on any side effects you’re having with Nexplanon. You can then share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • how soon you had the side effect after getting the implant
  • what your symptoms were
  • how it affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Nexplanon affects you. They can then use this information to adjust your treatment plan if needed.

Nexplanon may not be right for you if you have certain medical conditions. These are known as drug-condition interactions. Other factors may also affect whether Nexplanon is a good treatment option for you.

Talk with your doctor about your health history before getting Nexplanon. The list below includes factors to consider.

Diabetes or prediabetes. If you have diabetes or prediabetes, tell your doctor before getting Nexplanon. This drug may increase your blood sugar. If you have diabetes or prediabetes, your body may already have trouble regulating your blood sugar. So Nexplanon may make your condition worse. Your doctor may recommend monitoring your blood sugar more often during your Nexplanon treatment. In some cases, they may recommend a different birth control option for you.

Allergic reaction. If you’ve had an allergic reaction to Nexplanon or any of its ingredients, your doctor will likely not prescribe Nexplanon. Ask them what other medications are better options for you.

Blood clots. If you have blood clots or have had a blood clot in the past, your doctor will likely recommend a different kind of birth control for you. This is because Nexplanon can raise your risk of a blood clot occurring again. Talk with your doctor to determine which kind of contraceptive is best for you.

Liver problems. If you have liver problems, including liver tumors or liver disease, talk with your doctor before getting Nexplanon. Hormonal birth control such as Nexplanon can cause your liver problems to get worse. If you have certain kinds of liver problems, your doctor will likely recommend a different contraceptive option for you.

Breast cancer or other hormone-related cancer. If you’ve had breast cancer or other hormone-related cancer before, Nexplanon may raise your risk of it coming back. Your doctor will recommend a different kind of birth control for you.

Unusual genital bleeding. If you have unusual genital bleeding, tell your doctor before getting Nexplanon. In rare cases, genital bleeding may be a symptom of a more serious condition, such as cancer. Your doctor will want to determine what’s causing your genital bleeding before you get Nexplanon.

Kidney problems. If you have any kidney problems, tell your doctor before getting Nexplanon. Your doctor may recommend a kind of nonhormonal birth control if you have kidney problems.

Gallbladder disease. Hormonal birth control increases the risk of gallbladder disease. Nexplanon is a hormonal birth control, but it’s not known whether it can cause gallbladder disease. If you already have gallbladder disease, this medication may make your condition worse. Your doctor will determine whether Nexplanon is safe for you to get.

Depression. Hormonal birth control such as Nexplanon may cause mood changes, including depression. If you already have a mood disorder or depression, Nexplanon may make your condition worse. If you have one of these conditions, talk with your doctor before getting Nexplanon. They may monitor your mood more closely during your Nexplanon treatment. In some cases, they may recommend a different birth control option for you.

High blood pressure. Nexplanon may raise your blood pressure. If you already have high blood pressure, getting Nexplanon may make your condition worse. Your doctor may recommend monitoring your blood pressure more often during your Nexplanon treatment. In some cases, they may recommend a different birth control option for you.

High triglycerides or cholesterol. Nexplanon may raise your triglyceride or cholesterol levels. If your levels are already high, Nexplanon may make your condition worse. Your doctor may recommend monitoring your triglycerides and cholesterol levels through blood tests during your treatment with Nexplanon. In some cases, your doctor may prescribe treatment for your high triglycerides or cholesterol levels.

Pregnancy. You should not get Nexplanon during pregnancy. To learn more, see the “Pregnancy and breastfeeding with Nexplanon” section below.

Alcohol and Nexplanon

It should be safe to drink alcohol during your Nexplanon treatment. But alcohol may make certain side effects of Nexplanon worse. For example, both Nexplanon and alcohol can cause headache, nausea, and liver problems. So drinking alcohol while you have Nexplanon may make these side effects worse.

If you drink alcohol, talk with your doctor about how much is safe for you to drink during treatment with Nexplanon.

Pregnancy and breastfeeding with Nexplanon

Nexplanon should not be used during pregnancy. It’s used to help prevent pregnancy, so it shouldn’t be inserted if you’re already pregnant.

But like other kinds of birth control, Nexplanon is not 100% effective. So it’s still possible (although unlikely) to become pregnant during treatment with Nexplanon. In studies, Nexplanon was more than 99% effective at preventing pregnancy.

If you become pregnant during your Nexplanon treatment, be sure to tell your doctor right away. They’ll likely remove the Nexplanon implant.

It’s likely safe to have Nexplanon inserted if you’re breastfeeding. The drug in Nexplanon, etonogestrel, has been shown to pass into breast milk. But there haven’t been side effects reported in children who were exposed to etonogestrel through breast milk.

It’s important to note that Nexplanon may decrease milk production, which may make breastfeeding more difficult.

If you’re pregnant or breastfeeding, or planning to become pregnant or to breastfeed, talk with your doctor before getting Nexplanon.

Some people may experience side effects with Nexplanon. If you have questions about possible side effects, talk with your doctor. Questions you may want to ask include:

  • How will you treat side effects I have with Nexplanon?
  • Can you change my dose of Nexplanon to relieve side effects that I’m experiencing?
  • What should I do if I become pregnant during treatment with Nexplanon?

To learn more about Nexplanon, see these articles:

To get information on different conditions and tips for improving your health, subscribe to any of Healthline’s newsletters. You may also want to check out the online communities at Bezzy. It’s a place where people with certain conditions can find support and connect with others.

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.