Emgality (galcanezumab-gnlm) is prescribed for migraine prevention and to treat cluster headaches. Emgality may cause mild side effects and serious side effects.

Specifically, Emgality is used in adults to:

  • Prevent migraine attacks: For migraine, Emgality is a long-term treatment used on a regular basis to prevent migraine attacks. It’s not used for fast-acting relief of symptoms.
  • Treat cluster headache episodes: For this purpose, you start using Emgality to treat your cluster headache when an episode starts. Once your symptoms are relieved, you stop using it.

Emgality is a biologic medication. Biologics are drugs made from living cells. Emgality is given by subcutaneous injection (an injection under your skin). For more information about Emgality, see this Emgality overview article.

Like all medications, Emgality can cause side effects in some people. The most common of these are reactions that happen at the injection site, such as:

Learn more about Emgality’s side effects in the next sections.

Emgality can cause mild side effects. These include:

  • reactions at the injection site
  • rash
  • hives

In most cases, these side effects are temporary. And some may be easily managed. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And do not stop using Emgality unless your doctor tells you to.

To learn more about Emgality’s mild side effects, see the drug’s prescribing information.

A rash or hives could also be signs of a more serious allergic reaction to Emgality. Some people may experience a severe rash or hives, or a rash or hives along with difficulty breathing or swelling in the face or throat. If this happens, call 911 or your local emergency number, or seek emergency medical care. (See “Severe allergic reaction” under the “Side effects explained” section for more details.)

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

Emgality may cause rare but serious side effects. Talk with your doctor about your risk while using Emgality.

Serious side effects of Emgality can include severe allergic reactions. (To learn more, see “Side effects explained” later in this article.)

If you have side effects that feel serious or life threatening, call 911 or your local emergency number, or seek emergency medical care. And keep in mind that you may not have an allergic reaction right away. Symptoms of an allergic reaction could start days after giving yourself a dose of Emgality. So continue watching for symptoms on the days between injections.

Find answers to some frequently asked questions about Emgality’s side effects.

Is weight loss a side effect of Emgality?

No, Emgality should not cause weight loss. This side effect wasn’t seen in studies of the drug. If you have unexplained weight loss while using Emgality, talk with your doctor.

Does the Emgality injection cause side effects?

Possibly. Reactions at the injection site are the most common side effects of Emgality.

Emgality comes as a solution that you’ll give yourself by subcutaneous injection (an injection under your skin). Some people may experience mild or temporary skin discoloration, swelling, itching, or pain at the injection site. See “Side effects explained” later in this article for more details.

If you’re having difficulty giving yourself the injections, ask your doctor or pharmacist for help.

Can Emgality cause anxiety?

No, anxiety isn’t a side effect of Emgality. Anxiety wasn’t reported in studies of the drug. However, migraine is common in people with anxiety disorders or depression.

If you think you have untreated anxiety or another mental health condition, talk with your doctor.

Can constipation be a side effect of Emgality?

No, Emgality shouldn’t cause constipation. This side effect wasn’t seen in studies of the drug.

Some fast-acting headache pain relievers, such as acetaminophen with codeine, can cause constipation. This occurs because opioid drugs, including codeine, can slow your bowel movements.

If you’re unable to pass stools or are having other bowel problems while using Emgality, contact your doctor.

Can fatigue be caused by Emgality?

No. Fatigue (low energy) isn’t a side effect of Emgality. Fatigue wasn’t reported in studies of the drug. But if you have frequent migraine attacks, this may cause fatigue.

If you have low energy during your Emgality treatment, talk with your doctor about ways to manage it.

Learn more about some of the side effects that Emgality may cause.

Injection-site reactions

Reactions at the injection site are the most common side effects of Emgality.

Emgality is a solution that you’ll give yourself by subcutaneous injection (an injection under your skin). Some people may experience mild or temporary skin discoloration, swelling, itching, or pain at the injection site.

What might help

If you have difficulty giving yourself Emgality injections, or if you have side effects after injecting the drug, talk with your doctor. They can help train you or your caregiver to administer the drug. Your doctor may also suggest ways to manage any side effects.

For more tips on giving yourself Emgality injections, see these instructions for use.

Severe allergic reaction

In rare cases, Emgality may cause severe allergic reactions.

An example of a severe allergic reaction that could occur with Emgality is anaphylaxis. However, it’s important to note that anaphylaxis wasn’t seen during studies of the drug. There have been reports of this side effect in people using Emgality, but it’s unclear how often this has happened or whether Emgality was the cause.

Anaphylaxis is a life threatening allergic reaction that requires emergency medical care. Symptoms can include:

  • itching
  • nausea
  • a skin rash or hives
  • slurred speech or confusion
  • wheezing or difficulty breathing

Some people may also experience angioedema (swelling deep within and under the skin) during their Emgality treatment. However, angioedema wasn’t seen during studies of Emgality. There have been reports of this side effect, but it’s unclear how often this has happened or if Emgality was the cause.

With angioedema, the swelling typically occurs in your eyelids, lips, throat, hands, or feet. If angioedema affects your face or throat, it could close your airways and make it hard to breathe. Angioedema can occur with other symptoms of anaphylaxis, or it can occur on its own.

What might help

You should not use Emgality if you’ve ever had an allergic reaction to this drug or any of its ingredients, even if your symptoms were mild. Tell your doctor if you or a family member has experienced angioedema.

While using Emgality, watch for symptoms of an allergic reaction, including swelling or difficulty breathing. Call your doctor if you have these symptoms. If your symptoms feel life threatening, call 911 or your local emergency number, or seek emergency medical care.

Keep in mind that an allergic reaction may not occur until days after an injection. It’s important to continue watching for symptoms on the days between injections.

If you have a severe allergic reaction, stop using Emgality. Your doctor will recommend another drug to manage your condition.

Keeping track of side effects

During your Emgality treatment, consider keeping notes about any side effects you’re having. Then, you can 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 like:

  • what dosage you were taking when you had the side effect
  • how soon after starting that dosage you noticed the side effect
  • the symptoms you experienced
  • how they affected your daily activities
  • any other medications you were taking
  • any other information you feel is important

Keeping these notes and sharing them with your doctor will help them learn more about how Emgality affects you. And your doctor can use this information to adjust your treatment plan, if needed.

Emgality 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 Emgality. This section discusses some factors to consider.

Allergic reaction: If you’ve had an allergic reaction to Emgality or any of its ingredients, you should not use Emgality. Ask your doctor what other medications are better options for you.

Alcohol and Emgality

It’s generally safe to drink alcohol while using Emgality. However, alcohol may trigger migraine attacks or cluster headache symptoms.

Also, alcohol can harm your liver, and certain headache pain relievers that contain acetaminophen (Tylenol) can cause this damage, too. Drinking alcohol with these pain relievers can raise your risk of liver problems. So, you should avoid alcohol if you take acetaminophen products.

If you drink alcohol, ask your doctor how much is safe for you to drink with your condition and treatment plan.

Pregnancy and breastfeeding while using Emgality

It’s not known whether Emgality is safe to use during pregnancy or while breastfeeding.

If you’re currently pregnant or breastfeeding, or planning to become pregnant or breastfeed, talk with your doctor before using Emgality.

Emgality may give you more migraine-free days or help relieve your cluster headache symptoms. But while using Emgality, some people may experience mild reactions at the injection site (such as pain or swelling). And in rare cases, Emgality may cause a serious or life threatening allergic reaction.

If you have questions about Emgality’s side effects, talk with your doctor or pharmacist. They can help answer questions such as:

  • What are some tips to help prevent injection-site reactions when using Emgality?
  • If I have a mild allergic reaction (like a rash) that goes away, can I keep using Emgality?
  • How can I tell the difference between an injection site reaction and an allergic reaction?
  • What can I do to manage injection site reactions?

To learn more about Emgality, see these articles:

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Q:

I’m worried about a delayed serious allergic reaction with Emgality. Do I need to keep an epinephrine pen (EpiPen) handy, just in case?

Anonymous

A:

Probably not. Severe allergic reactions that require an EpiPen, such as anaphylaxis, were not reported in studies of Emgality. So, it’s unlikely that you’ll need to use an EpiPen. But if you’re worried about a delayed serious allergic reaction, talk with your doctor about whether an EpiPen prescription is right for you.

The Healthline Pharmacist TeamAnswers 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.