Key takeaways:
Emgality (galcanezumab) is an injectable prescription medication used for migraine prevention. It works by blocking a protein called calcitonin gene-related peptide (CGRP).
Injection site reactions, such as redness, pain, and itching where the medication was administered, are common Emgality side effects. But it can also cause antibody development, common cold symptoms, and back or joint pain.
You can often manage mild Emgality side effects at home. But if you have symptoms of a serious side effect, you should contact your healthcare team right away.
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Migraines can seriously disrupt your daily routine. They can cause throbbing head pain, sensitivity to light and sound, and nausea. Understandably, addressing these symptoms is a priority — especially if they happen often.
Emgality (galcanezumab) is one management option you may have heard of. This injectable medication is a monoclonal antibody that works by blocking calcitonin gene-related peptide (CGRP). This protein is involved in migraine pathways such as pain signaling and blood vessel changes in the brain. By blocking CGRP, Emgality can help prevent migraine symptoms over time. It can also treat cluster headaches, a type of headache that stirs up severe pain on one side of the head.
For most people, Emgality is well tolerated. But if you’re prescribed Emgality, there are still some side effects you should be aware of.
Emgality side effects at a glance
Emgality can cause a few different side effects to watch out for.
Relatively common and mild Emgality side effects include:
Injection site reactions
Sinus and throat infections
Runny nose
Less common risks include:
Antibody development
Anaphylaxis
Hypersensitivity reactions
Here, we’ll discuss five notable Emgality side effects and how you can manage them.
1. Injection site reactions
Emgality is injected under the skin once a month. You can inject the medication into your stomach or the front of your thighs. If you don’t want to inject the medication yourself, another person can inject the medication in the back of your upper arm or buttocks.
Regardless of where it’s injected, injection site reactions are common — especially after your first dose. These reactions may appear as redness, pain, and itching in the area where the injection was given.
Thankfully, most of these reactions are mild. They also tend to improve the day after receiving the injection.
Managing injection site reactions
To lessen the chance of injection site reactions, it’s best to wash your hands and clean your injection site with an alcohol wipe before you inject the medication. This helps lower the risk of infection.
Try to change the location of your injection site with each dose, as well. You can do this by switching arms or areas on your stomach, thighs, or buttocks with each dose. It’s also best to avoid injecting the medication into the belly button area, scar tissue, or areas where the skin is red or feels sore. You should also wait 30 minutes for the medication to come to room temperature to help minimize injection discomfort. Cold injections can hurt more.
Reach out to your healthcare team if your injection site reactions still bother you after a few days. This could be a sign that you aren’t injecting Emgality correctly. You can also ask them if it’s safe for you to take over-the-counter (OTC) pain relievers such as acetaminophen (Tylenol) or ibuprofen (Motrin, Advil).
2. Antibody development
Your body may gradually develop antibodies to Emgality. These are called anti-drug antibodies. These antibodies can bind to Emgality and may reduce how well it works over time.
In three Emgality clinical trials, anti-drug antibodies were seen in up to about 9% of people receiving this medication. These antibodies were also detected in nearly 2% of people who received placebo injections. So far, studies haven’t shown that these antibodies cause new safety problems, but they may make Emgality less effective for some people.
Tell your healthcare team if your migraines are coming back and the medication doesn’t seem to be working like it used to. They may switch you to another medication if they suspect you’ve developed antibodies to Emgality.
3. Common cold symptoms
Emgality may cause common cold symptoms, such as a runny nose or sore throat.
If you develop mild cold symptoms, regardless of whether you think it’s related to Emgality, try to get plenty of rest and stay hydrated. Depending on your symptoms, there are also home remedies and OTC products that can offer short-term relief. The best treatment option will depend on your symptoms.
For instance, if you have a sore throat, try gargling warm salt water or asking your healthcare team if it’s safe to take OTC pain relievers, such as ibuprofen. Nasal decongestants, such as pseudoephedrine (Sudafed), might be an option for temporary relief if you have a stuffy nose. But keep in mind that decongestants should be avoided in people with high blood pressure or diabetes.
Most common cold symptoms should clear up on their own after a few days. If they don’t, talk to your healthcare team. If they suspect your symptoms are caused by a bacterial infection rather than a virus, taking an antibiotic may be necessary.
4. Back or joint pain
Some people receiving Emgality have occasionally reported back or joint pain. Experts don’t fully know why this happens. Thankfully, this side effect tends to be mild to moderate in severity.
Depending on your symptoms, you can try gentle stretching or applying ice or heat to help ease discomfort. When needed, OTC medications, such as ibuprofen or naproxen (Aleve, Naprosyn), can temporarily help relieve joint and muscle pain.
Let your healthcare team know if your back or joint pain becomes persistent, bothersome, or gets worse at any point. They can determine if it’s caused by Emgality or something else and come up with a personalized plan to manage it.
5. Allergic reactions
As with all medications, Emgality may cause allergic reactions in some people. Mild symptoms of an allergic reaction can include itching, hives, and skin rashes. More serious symptoms can include trouble breathing and swelling of the face, lips, or tongue (anaphylaxis).
Stop administering Emgality and seek emergency medical care right away if you have breathing difficulties or swelling of the lips, mouth, or tongue. If your symptoms feel mild, it’s still a good idea to check in with your healthcare team and ask about next steps.
Keep in mind: Injection site reactions and mild allergic reactions can look similar. Both may include symptoms such as itching and redness. Talk to your healthcare team if you aren’t sure what’s causing your symptoms.
Does Emgality have less side effects than other migraine medications?
Generally speaking, yes. Emgality has fewer side effects than triptans, a popular group of migraine medications. This is because triptans narrow blood vessels in certain parts of your body. This raises the risk of:
Heart attacks
Stroke
High blood pressure
People with heart problems should generally avoid taking triptans. By comparison, Emgality doesn’t work by narrowing blood vessels, so it may be an option for some people with heart disease, high blood pressure, or a history of stroke. Your healthcare team will still weigh your individual risks and benefits.
What’s more, triptans may cause rebound headaches. These types of headaches happen when you take too much medication. Emgality hasn’t been connected to this.
Triptans aside, specific CGRP medication side effects can slightly vary by drug and formulation. For example, Aimovig (erenumab) is an injectable medication that’s similar to Emgality, but it’s been linked to high blood pressure within the first week of treatment. And if you’re receiving an oral CGRP medication (“gepant”), such as Nurtec ODT (rimegepant), stomach-related side effects like nausea and upset stomach are possible.
Does Emgality have any long-term side effects?
Emgality is considered a long-term maintenance medication. It’s designed to prevent migraines over time. So it’s normal to wonder if Emgality will cause side effects that will linger or won’t go away.
The short answer: It’s not too likely.
In one 12-month study, about 95% of people continued Emgality without experiencing any serious side effects. Some side effects were reported throughout the study time frame, but they weren’t directly attributed to longer-term use. This includes reports of injection site reactions, constipation, elevated blood pressure, and the development of anti-drug antibodies. What’s more, measurements such as blood work, vital signs, and heart monitoring didn’t show any meaningful differences compared to people who didn’t receive Emgality.
At this time, there haven’t been any studies that analyze the medication’s risks and side effects beyond 1 year of treatment.
When should you contact your healthcare professional about Emgality side effects?
Emgality side effects — especially injection site reactions — should gradually improve as your body gets used to the medication. But make sure to tell your healthcare team if you have any side effects that continue to bother you or get worse at any point. They can help manage your symptoms or change your treatment plan altogether.
Certain side effects are also more serious than others. Contact your healthcare team immediately if you think you’re having an allergic reaction to Emgality. Call 911 if you’re having trouble breathing or experiencing swelling in your lips, mouth, or tongue. These symptoms are considered a medical emergency and warrant immediate care.
Frequently asked questions
Emgality is primarily used to prevent migraines for adults. Healthcare professionals tend to consider Emgality for people who experience at least 4 migraines per month. It can also treat adults who experience episodic cluster headaches.
When you’re ready for your dose, take Emgality out of the fridge. Let it sit at room temperature for about 30 minutes. Once this time has passed, clean your injection site with an alcohol wipe. You can inject Emgality under the skin of your stomach (at least 2 inches away from your belly button) or your thigh (at least 2 inches above your knee and below your groin). If you’d rather not inject it yourself, someone else can give the shot in your buttock or the back of your upper arm. Try to use a different spot each time you inject. This should help reduce skin irritation.
You’ll typically use Emgality long term to help prevent migraines. There’s no set time frame. After a few months, your healthcare team should check how well it’s working for you. If it’s helping and you’re not having bothersome side effects, you can continue using it for years.
For cluster headaches, you’ll use Emgality once a month during a cluster period and stop when the cycle ends.
Emgality probably won’t cause weight gain (or weight loss). But the likelihood of this risk isn’t fully clear. In a clinical trial, weight gain was rare overall and comparable to placebo. And outside of clinical trials, weight gain has only been reported anecdotally among some people who use it.
Talk to your healthcare team if you’re concerned about weight gain with Emgality.
No, anxiety wasn’t reported as a side effect of Emgality in clinical trials. But anxiety itself can make migraines more likely. If you’ve been feeling more anxious while taking Emgality, it’s a good idea to talk with your healthcare team.
No, brain fog isn’t a typical issue with Emgality. However, brain fog is a common symptom that can happen before, during, and after a migraine attack.
Emgality is primarily used to prevent migraines for adults. Healthcare professionals tend to consider Emgality for people who experience at least 4 migraines per month. It can also treat adults who experience episodic cluster headaches.
When you’re ready for your dose, take Emgality out of the fridge. Let it sit at room temperature for about 30 minutes. Once this time has passed, clean your injection site with an alcohol wipe. You can inject Emgality under the skin of your stomach (at least 2 inches away from your belly button) or your thigh (at least 2 inches above your knee and below your groin). If you’d rather not inject it yourself, someone else can give the shot in your buttock or the back of your upper arm. Try to use a different spot each time you inject. This should help reduce skin irritation.
You’ll typically use Emgality long term to help prevent migraines. There’s no set time frame. After a few months, your healthcare team should check how well it’s working for you. If it’s helping and you’re not having bothersome side effects, you can continue using it for years.
For cluster headaches, you’ll use Emgality once a month during a cluster period and stop when the cycle ends.
Emgality probably won’t cause weight gain (or weight loss). But the likelihood of this risk isn’t fully clear. In a clinical trial, weight gain was rare overall and comparable to placebo. And outside of clinical trials, weight gain has only been reported anecdotally among some people who use it.
Talk to your healthcare team if you’re concerned about weight gain with Emgality.
No, anxiety wasn’t reported as a side effect of Emgality in clinical trials. But anxiety itself can make migraines more likely. If you’ve been feeling more anxious while taking Emgality, it’s a good idea to talk with your healthcare team.
No, brain fog isn’t a typical issue with Emgality. However, brain fog is a common symptom that can happen before, during, and after a migraine attack.
The bottom line
The most common Emgality (galcanezumab) side effects are injection site reactions and common cold symptoms. More serious complications, such as allergic reactions, are also possible.
Most injection site reactions are mild and tend to improve on their own. Other side effects of Emgality can often be managed with home remedies or over-the-counter (OTC) medications. But you should seek immediate medical attention if you experience symptoms of a serious side effect, such as trouble breathing or swelling of your lips, mouth, or tongue.
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References
Camporeale, A., et al. (2018). A phase 3, long-term, open-label safety study of galcanezumab in patients with migraine. BMC Neurology.
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Cohen, J., et al. (2021). Immunogenicity of biologic therapies for migraine: A review of current evidence. The Journal of Headache and Pain.
Detke, H. C., et al. (2018). Galcanezumab in chronic migraine. Neurology.
Eli Lilly and Company. (2025). Emgality- galcanezumab-gnlm injection, solution [package insert].
National Headache Foundation. (n.d.). Medication overuse headache.
Pozo-Rosich, P., et al (2022). Long-term treatment with galcanezumab in patients with chronic migraine: Results from the open-label extension of the regain study. Current Medical Research and Opinion.
Schou, W. S., et al. (2017). Calcitonin gene-related peptide and pain: A systematic review. The Journal of Headache and Pain.
Tepper, D. (2019). Calcitonin gene-related protein (CGRP)- Targeted treatments for migraine prevention. Headache.
Tso, A. R., et al. (2017). Anti-CGRP monoclonal antibodies: The next era of migraine prevention. Current Treatment Options In Neurology.
