Dulera and Symbicort are not the same medication, but they’re close relatives. Both are combination inhalers that pair a steroid with the same long-acting bronchodilator (formoterol), and both are taken twice daily for asthma. The key differences come down to which steroid is inside, what conditions they’re approved to treat, and how they fit into newer asthma treatment strategies.
How the Ingredients Compare
Both inhalers contain formoterol, a fast-acting bronchodilator that relaxes airway muscles within minutes and keeps them open for about 12 hours. Where they differ is the steroid component. Dulera contains mometasone, while Symbicort contains budesonide. Both steroids reduce inflammation in the airways, but they’re chemically distinct compounds with slightly different potency profiles, which is why the dosing numbers don’t match up one-to-one.
Both are pressurized metered-dose inhalers (the canister-and-mouthpiece type you press and inhale from). The standard dosing schedule is the same: two puffs, twice a day.
Available Strengths
Dulera comes in three strengths: 50/5, 100/5, and 200/5 mcg. Symbicort comes in two: 80/4.5 and 160/4.5 mcg. The first number is the steroid dose and the second is the formoterol dose. Because the steroids are different, you can’t directly compare the numbers. For example, a “low dose” regimen is four puffs per day of Dulera 50/5 or four puffs per day of Symbicort 80/4.5, according to the American Lung Association’s comparative dosing chart. Having three strength options gives Dulera a slightly more granular step-up path, but both inhalers cover low, medium, and high dosing tiers.
FDA-Approved Uses
This is one of the most practical differences between the two. Symbicort is FDA-approved for both asthma and COPD. Dulera is approved for asthma only. If you have COPD, Dulera is not the standard choice, and your insurance is unlikely to cover it for that diagnosis. Dulera is currently approved for patients 5 years of age and older, while neither inhaler is meant for quick relief of sudden breathing problems.
SMART Therapy: A Major Clinical Difference
One of the biggest shifts in asthma management over the past several years is something called SMART therapy (Single Maintenance and Reliever Therapy). The idea is simple: instead of using one inhaler for daily prevention and a separate rescue inhaler for flare-ups, you use the same combination inhaler for both purposes. You take your scheduled doses every day and also use extra puffs as needed when symptoms break through.
SMART works because formoterol opens airways fast enough to act as a rescue medication, unlike the bronchodilator in some other combination inhalers. Since both Dulera and Symbicort contain formoterol, both are theoretically candidates. In practice, though, budesonide/formoterol (Symbicort) is the combination with extensive clinical trial data supporting SMART use. The American Academy of Allergy, Asthma & Immunology notes that there are currently no studies on using mometasone/formoterol (Dulera) for SMART. Some clinicians may still consider it off-label, with suggested maximum doses of 11 puffs per day for adults and 7 puffs per day for children, but Symbicort is the evidence-backed option for this approach.
If your doctor has discussed using your combination inhaler as both a controller and a rescue, that conversation almost certainly points toward Symbicort rather than Dulera.
Generic Availability and Cost
Symbicort has authorized generic versions available in the U.S., which has brought its cost down considerably. Dulera does not yet have a generic equivalent. As of early 2026, the FDA has not approved a generic Dulera. This means Dulera typically costs more out of pocket, and insurance formularies often favor Symbicort or its generics as the preferred option in this drug class. If you’re switching between the two for cost reasons, your doctor can help identify the equivalent dosing tier.
Side Effects
Because both inhalers deliver a steroid plus formoterol to the same location (your airways), their side effect profiles overlap significantly. The most common issues with either inhaler include throat irritation, headache, and oral thrush, a yeast infection in the mouth caused by inhaled steroid particles settling on your tongue and throat. Rinsing your mouth and spitting after each use reduces this risk with both medications.
Formoterol can cause a slight increase in heart rate or occasional palpitations in some people, and this risk is the same regardless of which inhaler delivers it. Serious side effects like adrenal suppression or bone density changes are possible with long-term use of any inhaled steroid at high doses, but the risk at standard doses is low for both products.
Switching Between the Two
Because the steroid components differ, switching from Dulera to Symbicort (or vice versa) isn’t as simple as picking up a different box. The doses aren’t interchangeable by number. Your doctor will match you to the equivalent potency tier. For most people, the transition is straightforward with no gap in symptom control, but the swap should always be guided rather than self-directed, especially if your asthma has been unstable.
The most common reasons people switch include insurance formulary changes, cost, a move to SMART therapy (which favors Symbicort), or individual tolerance. Some patients find one steroid causes less throat irritation than the other, though this varies from person to person and isn’t predictable in advance.