Tips for Managing Side Effects of Mepolizumab (Nucala)

Medically Reviewed by Neha Pathak, MD on May 04, 2023

As with any medication, you may have some side effects when you take mepolizumab (Nucala) to treat serious asthma or another inflammatory condition.

Most aren’t serious and are easily managed at home. Side effects also tend to go away within a few weeks as your body gets accustomed to the drug. But in some cases, they could be troublesome or even serious. 

That’s why it’s a good idea to know what to watch out for – and what to do if you notice any side effects while you take this drug.

Skin irritation at the injection site 

One of the most common side effects of mepolizumabis pain, redness, swelling, warmth, burning, or itching on the area of skin where you got the shot. 

You can take the shot in your thigh, arm, or abdomen/stomach area (as long as it’s not close to your belly button). 

If you give yourself shots, choose a time when you don’t need to do anything strenuous afterward in case the injection area is sensitive. Carefully follow your doctor’s instructions. Let the injector pen warm up at room temperature for at least 30 minutes before using it (never use a microwave, sunlight, or hot water to speed up the process). To avoid soreness and irritation, rotate injection sites every month. 

If you get shots at your doctor’s office, schedule your appointment on a day when you have some downtime. 

Headache and tiredness 

Other side effects commonly reported by people who take mepolizumab are headaches and fatigue. 

If you get headaches when you take the drug, ask your doctor if you can take over-the-counter pain medications. Or you can:

  • Apply heat or cold packs to your head or over your eyes
  • Massage your head, neck, or back
  • Rest in a dark, quiet room
  • Avoid lights, sounds, and electronics
  • Take a walk or do some light stretching exercises 

You might also feel very tired after using this medication. The first few times you take it, don’t plan any activity that requires you to be alert afterward, such as driving. 

When taking mepolizumab, keep up healthy sleep habits. Aim for 7-8 hours each night. If you have fatigue as a side effect, take the drug in the afternoon or at night and plan to go to bed early. Avoid other substances that can make you tired, such as alcohol. 

These side effects may lessen or go away over time. If they don’t, tell your doctor. 

Aches and pains

Some people have back pain and body aches when taking mepolizumab, but these symptoms are usually mild and go away in a few days. If your doctor approves, you can take over-the-counter pain medication to help with these symptoms. You can also try:

  • Cold packs or heating pads
  • Light stretching exercises
  • Body massage

Schedule your treatments later in the day when you don’t need to do any intense activity afterward. 

If you take mepolizumab for chronic rhinosinusitis with nasal polyps (CRSwNP), you may have a sore throat, joint stiffness, or discomfort. You may be able to manage these symptoms with over-the-counter pain relievers and home remedies.

For a sore throat, you might:

  • Drink warm or cold liquids, depending on which works better to soothe your throat.
  • Suck on ice cubes, a lollipop, hard candy, or a throat lozenge.
  • Avoid smoking and being in smoky or polluted places. 

You could get joint stiffness in your hands, feet, hips, knees, and spine. To ease the discomfort:

  • Place a heating pad or ice pack on the area for 15-20 minutes several times a day.
  • Take a warm bath.
  • Do low-impact movement, like walking or swimming. 
  • Take over-the-counter pain relievers. 

Tell your doctor if your symptoms last for more than a few days. 

Allergic reaction

While these side effects are rare, there’s a chance you could be allergic or have a serious reaction to mepolizumab. Signs of a serious reaction include: 

  • Wheezing or trouble breathing
  • Shortness of breath or coughing
  • Tightness in your chest
  • Swelling of your face, mouth, and tongue
  • Trouble swallowing
  • Fainting or dizziness

If you have any of these symptoms, seek medical care right away. 


Some people who took mepolizumab reported that they got shingles, a reinfection of the chickenpox (herpes zoster) virus that causes a painful rash. Doctors aren’t sure whether mepolizumab makes you more likely to get shingles. 

Early signs of shingles include burning or shooting pain, tingling, and itchy skin, usually on one side of your body or face. A few days later, you get a rash that looks like chickenpox. Its blisters generally scab over in a week to 10 days. 

There’s no cure for shingles. But your doctor may be able to prescribe medicine to help with symptoms or help the rash go away. If you get it, ask your doctor if you should keep taking mepolizumab.

To ease symptoms, you can try over-the-counter pain medicines if your doctor says that’s OK. To soothe itchy, irritated skin, use:

  • Wet compresses
  • Calamine lotion
  • Oatmeal baths (in which you add 1 cup of finely ground oatmeal into a tub full of lukewarm water)

Before you take mepolizumab, talk to your doctor about whether you’ve had chickenpox or been vaccinated for shingles. They may suggest getting the vaccine before you start the drug. 

Show Sources

SOURCES: “Risks & side effects.” 

FDA: Mepolizumab label.

Cleveland Clinic: “Headache,” “Back Pain: Causes and Treatment,” “Joint Pain.”

Harvard Medical School: “What to do when medication makes you sleepy.”

National Health Service UK: “Sore Throat.”

MedlinePlus: “Mepolizumab Injection,” “Shingles.”

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