Table of Contents

Nucala (mepolizumab) is a prescription biologic medicine that contains mepolizumab, an interleukin-5 antagonist monoclonal antibody. It targets IL-5 signaling, which is closely tied to eosinophil growth and survival. Eosinophils are a type of white blood cell that can drive inflammation in certain forms of asthma and other eosinophil-linked diseases.

Nucala is prescribed for several eosinophilic conditions, but the dosing schedule is not the same for everyone. How often you take it, how much you receive, and where the injection is given depend on the condition being treated and your age.

This guide breaks down Nucala’s dosing schedule for asthma, COPD, EGPA, and other approved uses so you know exactly what to expect.

Key Takeaways

  • Nucala is always given on a fixed maintenance schedule, with no loading dose required for any approved condition.
  • The standard Nucala dosing frequency is once every 4 weeks, regardless of indication, age group, or setting.
  • Dose amounts of Nucala differ by condition, with 100 mg used for asthma, nasal polyps, and eosinophilic COPD, and 300 mg used for EGPA and HES.
  • Pediatric asthma dosing is lower than adult dosing, with children aged 6 to 11 receiving 40 mg instead of 100 mg.
  • The 300 mg dose is administered as three separate 100 mg injections, all given on the same day and spaced apart at different sites.

What is Nucala used for?

Nucala is approved in the US for the following uses:

    • Add-on maintenance treatment for severe asthma with an eosinophilic phenotype in adults and children age 6 and older.
    • Add-on maintenance treatment for chronic rhinosinusitis with nasal polyps in adults.
    • Add-on maintenance treatment for inadequately controlled COPD with an eosinophilic phenotype in adults.
    • Treatment of eosinophilic granulomatosis with polyangiitis (EGPA) in adults.
    • Treatment of hypereosinophilic syndrome (HES) in age 12 and older.

Nucala works over time to reduce inflammation but does not provide immediate relief. It cannot stop a sudden asthma attack or sudden airway tightening in COPD. Your rescue inhaler and personalized COPD or asthma action plan are still important for managing sudden symptoms.

Nucala coupons and discounts

How is Nucala administered?

Nucala is given as a subcutaneous injection into the upper arm, thigh, or abdomen. It comes in several forms:

    • A single-dose vial of lyophilized powder that must be mixed and injected by a healthcare professional
    • Prefilled autoinjectors and prefilled syringes for home use when appropriate, including a 40 mg prefilled syringe for certain pediatric asthma patients

When Nucala is given in a clinic using a vial, your dosing schedule is tied to appointment availability. When you use a prefilled device at home, scheduling is more flexible.

Nucala’s dosing schedule for adults and pediatric patients

Nucala is started at the full maintenance dose, with no loading dose required. Dosing is fixed and does not depend on body weight. The table below summarizes the recommended Nucala doses.

Condition Age group Dose Frequency
Severe asthma with an eosinophilic phenotype 12 years and older 100 mg Once every 4 weeks
Severe asthma with an eosinophilic phenotype 6 to 11 years 40 mg Once every 4 weeks
Chronic rhinosinusitis with nasal polyps Adults 100 mg Once every 4 weeks
COPD with an eosinophilic phenotype Adults 100 mg Once every 4 weeks
Eosinophilic granulomatosis with polyangiitis (EGPA) Adults 300 mg Once every 4 weeks
Hypereosinophilic syndrome (HES) 12 years and older 300 mg Once every 4 weeks

For EGPA and HES, a 300 mg dose is given as three separate 100 mg injections, spaced at least 5 cm apart, which is about 2 inches.

Severe eosinophilic asthma dosing schedule

For severe asthma with an eosinophilic phenotype, Nucala is an add-on maintenance treatment. The approved schedule is:

    • Ages 12 years and older: 100 mg once every 4 weeks
    • Ages 6 to 11 years: 40 mg once every 4 weeks

A caregiver may administer the 40 mg prefilled syringe after the healthcare provider decides it is appropriate and after training. Because kids have school and family routines, some families plan injection day for a weekend morning. It helps avoid rushing and makes post-injection observation easier.

What to expect

In the 32-week MENSA trial, people taking mepolizumab had about 53% fewer asthma flare-ups overall. The most serious flare-ups, those that led to an emergency room visit or hospital stay, dropped by about 61%.

Breathing also improved. After 32 weeks, lung function increased by about 100 mL, meaning patients were able to move more air out of their lungs compared with those who did not receive the medication.

People also reported feeling better day to day. Quality-of-life scores improved by about 6 to 7 points, which is considered a meaningful change, and asthma control scores improved by about 0.4 points, reflecting fewer symptoms and better overall control.

Immediate changes are not always obvious. Many people first see fewer asthma flare-ups and less need for oral steroids or urgent medical visits, while everyday symptoms tend to improve more slowly.

Chronic rhinosinusitis with nasal polyps dosing schedule

Chronic rhinosinusitis with nasal polyps (CRSwNP) often brings nasal blockage, drainage, reduced smell, and repeated need for oral steroids or surgery. Nucala is approved as an add-on maintenance treatment for adults with inadequate response to nasal corticosteroids. Nucala does not replace nasal corticosteroids.

The approved dose of Nucala for CRSwNP is 100 mg once every 4 weeks.

What to expect

In adults with severe chronic sinusitis and nasal polyps that kept returning despite standard treatment, adding mepolizumab led to measurable improvements over one year. Nasal polyp size decreased more with mepolizumab than with placebo, with endoscopic scores improving by about 0.7 points, and nasal blockage symptoms improved by about 3 points on a 10-point scale, reflecting easier breathing through the nose.

Mepolizumab was generally well tolerated. Treatment-related side effects occurred in 15% of patients taking mepolizumab compared with 9% on placebo, and serious side effects occurred at similar rates (6% in both groups), with no new safety concerns identified.

In adults with severe nasal polyps who were likely to need another sinus surgery, treatment with mepolizumab reduced the risk of further surgery by about half over one year.

Mepolizumab also reduced the likelihood of actually needing sinus surgery, regardless of how recently someone had their last surgery or how high their eosinophil levels were at the start of the study. This suggests mepolizumab can help delay or avoid repeat sinus surgery for many people with hard-to-treat nasal polyps.

COPD dosing schedule

Nucala is now FDA-approved as an add-on maintenance treatment for adults with inadequately controlled COPD and an eosinophilic phenotype. The approved Nucala dose for COPD is 100 mg once every 4 weeks.

What to expect

In the MATINEE trial, patients with COPD and an eosinophilic phenotype who were already receiving triple inhaled therapy were included.

Adding mepolizumab reduced moderate or severe flare-ups by about 21% and helped people go about 23% longer before their first flare-up, without increasing side effects compared with placebo.

Measures of health-related quality of life and symptom scores did not differ significantly between groups. The incidence of adverse events was similar in the mepolizumab and placebo groups.

EGPA dosing schedule

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare vasculitis condition that often includes asthma, sinus disease, and systemic involvement. The approved Nucala dose for EGPA is 300 mg once every 4 weeks.

As mentioned earlier, the 300 mg dose is delivered as three 100 mg injections. Each injection should be administered at least 5 cm or approximately 2 inches apart.

Because all three injections are given on the same day, plan a bit of extra time. Many people find the thigh or abdomen easier for multi-injection dosing, since these areas allow enough space to separate injection sites comfortably.

Many people with EGPA also take oral corticosteroids or other immunomodulating medications. Note that any changes to steroid dosing should be done under medical supervision. Stopping or reducing steroids on your own, including inhaled steroids, can cause symptoms that were previously controlled to return.

What to expect

In people with EGPA, treatment with mepolizumab helped more patients reach remission and stay in remission longer than placebo. About 32% of patients were in remission at both 9 and 12 months, compared with 3% on placebo, and flare-ups were reduced by about 50% over one year.

Mepolizumab also made it easier to lower steroid use. By the end of the study, 44% of patients taking mepolizumab were able to reduce their daily steroid dose to 4 mg or less, compared with 7% of those on placebo, without new safety concerns.

Hypereosinophilic syndrome dosing schedule

Hypereosinophilic syndrome (HES) is a group of conditions where eosinophils are elevated and cause damage or symptoms across organ systems.

Nucala is approved for adult and pediatric patients aged 12 years and older who have had long-lasting HES for 6 months or more, and doctors have ruled out other common causes of high eosinophils. Examples of excluded causes include parasite infections, allergies, asthma alone, or drug reactions.

The approved Nucala dose for HES in both adults and teens (12 to 17 years of age) is 300 mg once every 4 weeks. Again, 300 mg is given as three 100 mg injections, and each injection should be spaced at least 5 cm (2 in) apart.

What to expect

In people with HES, continuing treatment with mepolizumab helped keep the condition under better control over time. During the extension study, flare-ups were uncommon, with patients averaging well under one flare per year, especially among those who had already been taking mepolizumab.

Mepolizumab also helped reduce reliance on steroids. About 28% of patients were able to cut their daily oral steroid dose by at least half, and blood eosinophil levels dropped by about 89% in patients who had previously been on placebo and stayed low in those already receiving treatment.

Side effects were generally manageable, with no treatment-related deaths reported.

How to prepare and use Nucala prefilled autoinjectors and syringes

The 100 mg/mL prefilled autoinjector and 100 mg/mL prefilled syringe are approved for adults and adolescents aged 12 years and older. You may inject Nucala yourself, or a caregiver may give the injection, once your healthcare provider determines it is appropriate.

The 40 mg/0.4 mL prefilled syringe is approved for children aged 6 to 11 years. This dose must be given by a healthcare provider or by a trained caregiver, based on your provider’s guidance.

Before using Nucala, you or your caregiver should receive proper training in subcutaneous injection technique and in the preparation and administration of the medication.

Here’s a step-by-step guide to using Nucala safely:

  • Bring to room temperature – Remove the prefilled autoinjector or prefilled syringe from the refrigerator and allow it to sit at room temperature for 30 minutes before injection. Do not warm Nucala in any other way.
  • Inspect the medication – Before injecting, visually inspect the window of the prefilled autoinjector or syringe. Nucala should appear clear to slightly opalescent and colorless to pale yellow or pale brown. Do not use the injection if you see cloudiness, discoloration, or particles. Do not use the device if it has been dropped on a hard surface.
  • Choose an injection site – Inject Nucala under the skin of the upper arm, thigh, or abdomen, avoiding the area within 5 cm (about 2 inches) of the navel.
  • Rotate injection sites when needed – If you are being treated for EGPA or HES, make sure each injection site is at least 5 cm (about 2 inches) away from the previous site.
  • Avoid problem areas – Never inject into skin that is tender, bruised, red, or hard.
  • If you miss a dose – If you miss a dose, take it as soon as possible. After that, return to your usual dosing schedule. If your next dose is already due, take the dose as planned.
  • Use it once, then discard it – Each prefilled autoinjector is designed for a single injection only. After you use it, you must throw it away in a sharps container, even if there appears to be medicine left.
  • Never share it with anyone else – Sharing an autoinjector can spread serious infections between people. It is for one person only.
  • Do not use it if it was dropped or damaged – If the autoinjector falls onto a hard surface or looks cracked, bent, or broken, it may not work properly or may no longer be sterile. In that case, do not inject it and dispose of it safely.

How to switch Nucala from clinic injections to at-home use

Switching from clinic-administered Nucala to at-home injections is possible and does not change your dose or schedule. It only changes how and where the injection is given.

Here’s what you need to do:

1. Talk with your healthcare provider first

Your doctor must confirm that at-home dosing is appropriate for you. This usually depends on:

    • How long you have been on Nucala
    • Whether you have tolerated injections without serious reactions
    • Your comfort level with self-injection or having a caregiver help

If approved, your prescription is updated from a clinic-only vial to a prefilled autoinjector or prefilled syringe.

2. Receive training before your first home dose

Before you inject at home, you or your caregiver should receive hands-on training. This may happen:

    • During a clinic visit
    • Through a nurse-led education session
    • With manufacturer-provided training materials

Training covers injection technique, site selection, storage, and what to do if you miss a dose.

3. Switch the product form

The dose and timing do not change when you move to home use. If you were receiving 100 mg every 4 weeks, you continue with 100 mg every 4 weeks. If you require 300 mg, you still take three 100 mg injections on the same day.

The only difference is that injections are now given using prefilled devices instead of a clinic-prepared vial.

4. Coordinate pharmacy delivery and storage

Once approved, Nucala is typically shipped to your home by a specialty pharmacy. You will need to:

    • Store it in the refrigerator at 36°F to 46°F (2°C to 8°C). It can remain unrefrigerated up to 86°F (30°C) for no more than 7 days if the carton is unopened. If it exceeds that time, it must be discarded.
    • Leave it in the original carton to protect it from light.
    • Once removed from the carton, it should be used within 8 hours after removal, or safely thrown away if unused.
    • Keep it away from freezing temperatures, excessive warmth, and agitation.

5. Keep follow-up appointments

Even after switching to at-home dosing, regular follow-ups remain important. Your provider will continue to monitor:

    • Symptom control and flare-ups
    • Side effects
    • Whether at-home dosing remains appropriate

If problems arise, clinic dosing can be resumed if needed.

Bottom line

Nucala is a once-every-four-weeks add-on treatment for eosinophil-driven conditions such as severe asthma, nasal polyps, eosinophilic COPD, EGPA, and hypereosinophilic syndrome. Dosing is fixed by condition and age, with higher doses for EGPA and HES given as multiple injections on the same day.

Clinical studies show that Nucala reduces flare-ups, lowers steroid use, and improves disease control over time, but it does not provide immediate relief and does not replace rescue medications. Whether given in a clinic or at home, proper training, consistent dosing, safe handling, and regular follow-up are essential for long-term management.

Related Articles

Frequently Asked Questions

Nucala is given once every 4 weeks as a subcutaneous injection. This monthly schedule applies across its approved conditions. The dose timing should stay consistent to maintain stable eosinophil control.

The 100 mg dose is used for severe eosinophilic asthma, chronic rhinosinusitis with nasal polyps, and eosinophilic COPD. It helps lower eosinophil-driven inflammation that contributes to symptoms. Higher doses are used for some rare eosinophilic disorders.

Nucala has been shown in clinical research to significantly reduce asthma exacerbations in patients with severe eosinophilic asthma compared with placebo. In the MENSA trial, NUCALA reduced the annual rate of asthma exacerbations by 53% compared with placebo. In real-world observational studies, exacerbations dropped substantially, with some demonstrating 74% lower exacerbation rates after treatment compared with baseline.

Nucala is usually injected into the thigh, abdomen, or upper arm. The injection site should be rotated each month. Avoid areas that are bruised, tender, or scarred.

You should not stop corticosteroids suddenly when starting Nucala without medical guidance. Live vaccines are generally avoided unless approved by your healthcare provider. Always report new infections or allergic symptoms promptly.

Blood eosinophil levels begin to fall within days after the first injection. Symptom improvement may take several weeks. Full clinical benefit is often assessed after a few months of consistent treatment.

Most guidelines require a blood eosinophil count of at least 150 cells per microliter at initiation or 300 cells per microliter in the past year. These thresholds help predict who is most likely to benefit. Your doctor may also consider your exacerbation history.

In studies, people taking Nucala for asthma had about 53% fewer asthma flare-ups overall. The most serious flare-ups, those that led to an emergency room visit or hospital stay, dropped by about 61%.

Yes. In trials, lung function increased by about 100 mL, which means that patients were able to move more air out of their lungs. Quality-of-life and asthma control scores improved, reflecting fewer symptoms and better overall control.

Common side effects include headache, injection site reactions, back pain, and fatigue. Hypersensitivity reactions are rare but possible. Overall, it is considered well-tolerated in long-term studies.

Nucala is approved for nasal polyps in adults aged 18 years and older. Pediatric use for this condition is not approved.

Sources

Ortega, H. G., Liu, M. C., Pavord, I. D., Brusselle, G. G., FitzGerald, J. M., Chetta, A., Humbert, M., Katz, L. E., Keene, O. N., Yancey, S. W., & Chanez, P. (2014). Mepolizumab Treatment in Patients with Severe Eosinophilic Asthma. New England Journal of Medicine, 371(13), 1198–1207. https://doi.org/10.1056/nejmoa1403290

Sciurba, F. C., Criner, G. J., Christenson, S. A., Martinez, F. J., Papi, A., Roche, N., Bourbeau, J., Korn, S., Bafadhel, M., Han, M. K., Kolterer, S., Miller, K., Mouneimne, D., Fletcher, J., Mayer, B., Min, J., & Pavord, I. D. (2025). Mepolizumab to Prevent Exacerbations of COPD with an Eosinophilic Phenotype. New England Journal of Medicine, 392(17), 1710–1720. https://doi.org/10.1056/nejmoa2413181

Wechsler, M. E., Akuthota, P., Jayne, D., Khoury, P., Klion, A., Langford, C. A., Merkel, P. A., Moosig, F., Specks, U., Cid, M. C., Luqmani, R., Brown, J., Mallett, S., Philipson, R., Yancey, S. W., Steinfeld, J., Weller, P. F., & Gleich, G. J. (2017). Mepolizumab or Placebo for Eosinophilic Granulomatosis with Polyangiitis. New England Journal of Medicine, 376(20), 1921–1932. https://doi.org/10.1056/nejmoa1702079

Gleich, G. J., Roufosse, F., Chupp, G., Faguer, S., Walz, B., Reiter, A., Yancey, S. W., Bentley, J. H., Steinfeld, J., García, G. R., Pascale, P., Wehbe, L., Blockmans, D., Roufosse, F., Antila, M. A., Blanco, D., Pez, A. L. F., Faguer, S., Kahn, J., . . . Rothenberg, M. E. (2021). Safety and efficacy of mepolizumab in hypereosinophilic syndrome: an Open-Label Extension study. The Journal of Allergy and Clinical Immunology in Practice, 9(12), 4431-4440.e1. https://doi.org/10.1016/j.jaip.2021.07.050

Han, J. K., Bachert, C., Fokkens, W., Desrosiers, M., Wagenmann, M., Lee, S. E., Smith, S. G., Martin, N., Mayer, B., Yancey, S. W., Sousa, A. R., Chan, R., Hopkins, C., Emanuelsson, C. A., Ardusso, L., Armstrong, M., Bardin, P., Barnes, S., Bergna, M., . . . Kim, H. Y. (2021). Mepolizumab for chronic rhinosinusitis with nasal polyps (SYNAPSE): a randomised, double-blind, placebo-controlled, phase 3 trial. The Lancet Respiratory Medicine, 9(10), 1141–1153. https://doi.org/10.1016/s2213-2600(21)00097-7

Fokkens, W. J., Mullol, J., Kennedy, D., Philpott, C., Seccia, V., Kern, R. C., Coste, A., Sousa, A. R., Howarth, P. H., Benson, V. S., Mayer, B., Yancey, S. W., Chan, R., & Gane, S. B. (2022). Mepolizumab for chronic rhinosinusitis with nasal polyps (SYNAPSE): In?depth sinus surgery analysis. Allergy, 78(3), 812–821. https://doi.org/10.1111/all.15434

NUCALA (mepolizumab) Dosing & Administration | For HCPs. (2025). https://nucalahcp.com/egpa/dosing-and-administration/at-home/