Highlights
- Nasonex is a prescription steroid used to treat nasal allergy symptoms.
- It’s a well-known medication that’s generally considered safe for most people, but it has a wide range of side effects.
- You should consult with a doctor via telehealth or in-person visit before starting on Nasonex.
Nasonex has been on the market for decades, yet there can be some confusion about it to this day. Here’s what you need to know about Nasonex, who should use it and why, its dosage, and what to expect when you use it long-term.
What Is Nasonex?
Nasonex is the brand name of mometasone furoate, a steroid, more specifically, a glucocorticoid. Glucocorticoids are used as part of the feedback loop in your immune system; once they bind to certain receptors, the job of your body’s immune cells is done.
That’s how Nasonex offers relief for people with asthma during allergy season. Allergic reactions and asthma are both immune-system related, so Nasonex serves as a brake on overeager systems. It’s designed to reduce inflammation in the nose, so you can breathe more easily.
Who Can Use Nasonex?
Nasonex is approved for anybody over the age of two who experiences year-round allergies. For seasonal allergies, it’s recommended for people over the age of 12. Adults can also use Nasonex to treat nasal polyps.
It generally takes about two weeks of use before you’ll start seeing relief, and it’s recommended that you start before allergy season begins, to limit your discomfort.
Do I Need A Prescription For Nasonex?
Due to the side effects and potential risks of using mometasone furoate, it’s generally kept behind the counter. Pharmacists call drugs like Nasonex pleiotropic, meaning they can have a diverse and wide-ranging number of side effects across the body.
That’s due to how Nasonex works. Since it’s putting the brakes on your immune system, each person’s reaction to it will vary.
That said, Nasonex is widely prescribed, its common side effects are well understood, and outside of a few specific groups, it’s generally considered safe.
Who Shouldn’t Use Nasonex?
Nasonex isn’t recommended for people who have any of the following:
- Any chronic infection, regardless of where it is on your body
- Any active infection
- Glaucoma or cataracts or a history of them in your family
- Herpes simplex virus infection in your eyes
- Tuberculosis or any other infection or illness
- Sores or ulcers inside your nose
- Any nasal surgery or injury to your nose.
If you’re pregnant, considering pregnancy, or breast-feeding, you should discuss taking Nasonex with your doctor. If you’re currently using an antibiotic, antiviral, or antifungal medication, you’ll need to finish the course before you start using Nasonex. If you’re taking antidepressant medication, regardless of reason, you’ll need to check with your doctor about Nasonex as well.
In addition, you’ll need to be particularly careful around infection and illness. You’ll need to stay away from sick people as much as possible. And if you’re exposed to chickenpox or measles, seek out a doctor for preventative treatment immediately. Otherwise, you’re at risk of serious infection or death.
What Are the Side Effects of Nasonex?
Nasonex’s most common side effects are:
- Nosebleeds
- Headache
- Stuffy nose, sore throat, cough
- Flu-like symptoms
In addition, you should keep an eye out for the following symptoms, which are signs that Nasonex is having an effect beyond the nose:
- Weight gain, especially around the face, upper back, and torso
- Difficulty healing from injury, thinner skin, and more body hair
- Changes in periods or sexual functioning
- Muscle weakness or general fatigue
- Mood changes such as depression, anxiety, or feeling irritable
If you experience any of the following, contact a doctor immediately:
- Severe bleeding or increased drainage from your nose
- Nose pain or discomfort or headache
- White patches or sores in the nose that aren’t healing
- Wheezing or other problems breathing
- Vision problems
- Pain or full feeling in the ear, trouble hearing, or drainage from the ear
How Do I Use Nasonex?
Blow your nose gently first to clear any obstructions. Then, holding your head upright, insert the tube into one nostril and hold the other closed with your finger. Spray, then switch, until you’ve used as many sprays as your doctor prescribes.
Don’t blow your nose for a few minutes after use, and give your mouth a quick rinse before going about your day. This will help limit your risk of thrush and other fungal infections.
If you miss a dose or don’t use it at precisely the same time every day, that’s fine. Don’t double-dose.
Can I Use Nasonex Year-round?
In theory, you can use Nasonex daily. Contrary to urban legend, long-term Nasonex use won’t damage the tissues in your nose. In reality, though, perpetual use is probably not a great choice for everyone because Nasonex is a steroid.
Some people only know steroids from sports scandals, but they’re extremely common. The human body alone makes thirty different kinds and they’re found in almost every animal and plant on the planet.
Steroids help keep your electrolytes balanced, keep your immune system on an even keel, and do a host of other jobs. And like anything else, an unbalanced steroid load can begin having side effects over time.
What’s more, because Nasonex is designed to keep your immune system from overreacting, it has the potential to be over-protective and keep your system from reacting when you want it to. In some situations, the benefits may outweigh the risks, but in others, that may not be the case.
Still, some people do use Nasonex year-round. Whether that’s a good choice for you will depend upon your specific situation and your doctor’s recommendations.
Nasonex Is Safe for Allergy Symptoms
For most of us, there’s no reason to live in misery during allergy season. For many, Nasonex is an ideal way to limit allergy and asthma symptoms when the flowers bloom or the goldenrod grows. For daily, year-round use, however, you may want to check with your doctor first.
To learn more about Nasonex, visit our Nasonex page. To get a free telehealth consult with a U.S.-licensed physician to find out whether it’s right for you, call 1-800-467-5146.

Dan is a long-time freelance writer focusing on technology, science, health, and medicine, with a lifelong interest in physics, biology, and medicine. His work has taken a particular focus on scientific studies “beyond the headlines,” reading the study to more closely examine the results.