Which is better, Singulair or montelukast? Understanding the Difference

October 8, 2025 •

2 min read

The United States Food and Drug Administration (FDA) first approved generic montelukast in 2012, 14 years after its brand-name counterpart, Singulair, was introduced to the market. Given that montelukast is the generic version of Singulair, the question of which is better often centers on factors like cost, potential inactive ingredient differences, and individual patient tolerance.

Quick Summary

This article explains that Singulair is the brand-name drug for the active ingredient montelukast, and as a generic, montelukast is considered bioequivalent to Singulair. The key distinctions lie in cost and inactive ingredients, which may affect individual patient experiences. Important safety information, including an FDA boxed warning, applies to both versions.

Key Points

Bioequivalence: Montelukast is the generic version of Singulair and contains the exact same active ingredient.
No Difference in Efficacy: The FDA considers generic montelukast and brand-name Singulair equally effective for treating asthma and allergies.
Significant Cost Savings: Generic montelukast is considerably more affordable than brand-name Singulair, offering substantial cost savings.
FDA Boxed Warning: Both versions carry a serious FDA warning regarding potential neuropsychiatric side effects, including mood changes and suicidal thoughts.
Consult a Professional: Due to the potential for serious side effects, all treatment decisions should be made in close consultation with a healthcare provider.
Inactive Ingredients: Minor differences exist in inactive ingredients (fillers, colors), which may affect a small number of patients with sensitivities.

Understanding Brand vs. Generic Medications

A generic drug is a copy of a brand-name drug, becoming available after the original patent expires. The FDA ensures generic drugs are bioequivalent to their brand-name versions through a rigorous review process.

What Bioequivalence Means for Montelukast and Singulair

For FDA approval, generic drugs must:

Contain the same active ingredient(s).
Match the brand name's strength, dosage form, and administration route.
Be identical in quality, strength, purity, and stability.
Work the same way in the body and have the same intended uses.
Be manufactured under strict quality standards.

This means that Singulair and generic montelukast are medically interchangeable for most patients, offering the same therapeutic effect.

Key Differences Between Singulair and Montelukast

Although medically equivalent, practical differences exist.

Cost

The primary difference is cost; generic montelukast is significantly more affordable as manufacturers don't have the initial development expenses of the brand-name drug. This provides considerable long-term savings.

Inactive Ingredients

Inactive ingredients (like fillers or colors) can differ between generic and brand-name versions. While usually not affecting efficacy, a small number of patients might react to a specific inactive ingredient.

Pharmacokinetics

Studies indicate minimal difference in how generic and brand-name drugs are absorbed. FDA bioequivalence standards ensure that montelukast's absorption differences are clinically insignificant.

FDA Boxed Warning and Neuropsychiatric Side Effects

The FDA issued a Boxed Warning for montelukast (including Singulair) in 2020 due to reports of serious mental health side effects.

Symptoms of Concern

Agitation and aggression
Depression and anxiety
Irritability and restlessness
Trouble sleeping and vivid dreams
Memory impairment
Suicidal thoughts and actions

FDA Recommendations

For allergic rhinitis: Only use montelukast if other treatments are ineffective or not tolerated.
For asthma: Carefully consider risks and benefits before prescribing.
For all patients: Be aware of neuropsychiatric risks and contact a doctor if mood changes occur.

This warning applies to both Singulair and generic montelukast.

Singulair vs. Montelukast: A Comparison Table


Feature	Singulair	Montelukast (Generic)
Active Ingredient	Montelukast sodium	Montelukast sodium
Efficacy	Considered clinically equivalent to generic montelukast	Considered clinically equivalent to brand-name Singulair
Cost	Significantly more expensive	Significantly more affordable
FDA Approval	Approved in 1998	FDA-approved generic version available since 2012
Dosage Forms	Tablets, chewable tablets, and oral granules	Tablets, chewable tablets, and oral granules
Side Effects	Same common and serious side effects as generic	Same common and serious side effects as brand-name
Inactive Ingredients	May vary from generic versions	May vary from brand-name version

Conclusion: Making the Right Choice

When considering which is better, Singulair or montelukast, remember they are bioequivalent. Both effectively manage asthma and allergies with the same active ingredient. The main difference is cost, with generic montelukast being much more affordable. However, the FDA boxed warning regarding serious neuropsychiatric side effects for both versions necessitates discussing treatment options with a healthcare provider, especially for those with mental health history or when used for mild allergic rhinitis. While the generic offers cost savings, medical guidance is crucial to weigh the risks and benefits.

Frequently Asked Questions

Yes, generic montelukast is considered bioequivalent to Singulair by the FDA. This means it contains the same active ingredient and is expected to have the same therapeutic effect and safety profile.

The primary difference is cost, with generic montelukast being significantly less expensive. The brand-name and generic versions are identical in their active ingredient and how they work in the body, although inactive ingredients can vary.

The FDA issued a boxed warning for montelukast because of serious neuropsychiatric side effects, including agitation, depression, and suicidal thoughts, which have been reported in some patients.

Yes, serious mental health side effects are a risk with both brand-name Singulair and generic montelukast. You should discuss these risks with your healthcare provider and immediately report any mood or behavioral changes.

For asthma and allergic rhinitis, some patients may notice an effect within 24 hours, but it may take 1 to 2 weeks for the full benefit to be realized. It is not a rescue medication for an acute asthma attack.

While the active ingredient is identical, inactive ingredients (binders, colors) can differ. A very small number of people may have a sensitivity to an inactive ingredient in one version but not the other, though this is uncommon.

From an efficacy standpoint, neither is inherently better for allergies. The choice between them is typically based on cost. For mild allergic rhinitis, the FDA recommends considering alternative treatments first due to the neuropsychiatric side effect risk associated with montelukast.

Yes, because the active ingredient is the same, switching from Singulair to generic montelukast is generally seamless. There is no need to taper the dose. However, always consult your doctor before making any changes.