Yes. 38 FDA-approved labels for Montelukast carry a boxed warning, and its subject is serious neuropsychiatric events. A boxed warning is the most serious warning the FDA requires on a prescription label. It is applied to the drug and to the situations in which it is used, not to any particular person taking it.
What the warning says
Below is how the Montelukast warning opens on one specific label, identified underneath it. Of the 25 Montelukast labels sampled, 10 carried materially different wordings, and this was the most common, used by 16 of them.
WARNING: SERIOUS NEUROPSYCHIATRIC EVENTS Serious neuropsychiatric (NP) events have been reported with the use of montelukast sodium. The types of events reported were highly variable, and included, but were not limited to, agitation, aggression, depression, sleep disturbances, suicidal thoughts and behavior (including suicide). The mechanisms underlying NP events associated with montelukast sodium use are currently not well understood [see Warnings and Precautions ( 5.1 )]. Because of the risk of NP events, the benefits of montelukast sodium may not outweigh the risks in some patients, particularly when the symptoms of disease may be mild and adequately treated with alternative therapies.
MONTELUKAST SODIUM, A-S Medication Solutions, label version effective 05 March 2026. Opening of the warning; read the full label on DailyMed.Why the wording differs between manufacturers
There is no single official text of a boxed warning. The FDA sets what a warning must cover, and each manufacturer writes its own label within that. Of the 25 Montelukast labels sampled for this page, 10 carried materially different wordings of the same warning, and the version quoted above was used by 16 of them.
The hazard does not change between those 10 versions. Only the sentences do, which is why a refill from a different manufacturer can carry warning text that reads differently without anything about Montelukast or its risks having changed.
Montelukast is dispensed under 38 current FDA labels despite this warning, which is the point worth holding onto: a boxed warning is a disclosure requirement, not a verdict. What a boxed warning does and does not mean sets out the distinction.
Common questions
Does Montelukast have a black box warning?
Yes. 38 FDA-approved labels for Montelukast carry a boxed warning, and its subject is serious neuropsychiatric events. A boxed warning is the strongest warning the FDA requires on a prescription label, and it is applied to the drug, not to any individual taking it.
What does the Montelukast boxed warning say?
The wording is set by each manufacturer within FDA requirements, so it varies. In the version quoted on this page, taken from a label effective 05 March 2026, the warning concerns serious neuropsychiatric events. The full text is linked so the exact version can be read rather than summarised.
Does the Montelukast boxed warning mean the drug is unsafe or being withdrawn?
No. It means the FDA requires the risk of serious neuropsychiatric events to be communicated prominently so prescribers weigh it explicitly. Montelukast remains FDA-approved and is dispensed under 38 current labels. A boxed warning is a disclosure requirement, not a judgement that a drug should not be used.
Why do different pharmacies show different warning text for the same drug?
Because each manufacturer writes its own label within the FDA's requirements. Of 25 Montelukast labels sampled here, 10 carried materially different wordings of the same warning. The hazard described is the same; the sentences are not. This is a common source of confusion when a prescription is refilled with a different manufacturer's product.
Should I stop taking Montelukast because of this warning?
This page does not answer that and cannot. The warning about serious neuropsychiatric events is written for a prescriber deciding whether Montelukast suits a particular patient, and stopping a prescribed medicine carries its own risks that this page knows nothing about. Raise it with the prescriber or a pharmacist, who can see the whole picture.
Where this page's information comes from
The quotation above is from one Montelukast label, linked below by its DailyMed set identifier so the exact version can be opened rather than taken on trust. The figure of 38 labels, and the count of 10 distinct wordings among 25 sampled, were computed from the openFDA labelling API on 30 August 2026.
- MONTELUKAST SODIUM prescribing information, A-S Medication Solutions, effective 05 March 2026.
- openFDA drug labelling API, the source of the label counts and variant counts on this page.
Labels are revised over time. The version linked above is the one this page was written against, and a newer revision may differ. Counts reflect the labels present in openFDA on the retrieval date.