Montelukast Shortage Update: What Patients Need to Know in 2026

If you've had trouble filling your montelukast prescription lately, you may be wondering whether there's an official drug shortage. This page provides the most current information on montelukast supply — as well as practical advice if you're having trouble getting your prescription filled.

Current Montelukast Shortage Status (2026)

As of 2026, montelukast is NOT listed on the FDA's official drug shortage database. The national supply of generic montelukast is generally sufficient. Because montelukast (generic Singulair) has been off-patent since August 2012 and is manufactured by dozens of companies, it has built-in supply resilience that single-source drugs lack.

That said, individual patients across the country continue to report difficulty getting their prescriptions filled at specific pharmacies. These are localized, sporadic supply gaps — not a national shortage — and typically resolve within a few days with persistence or by switching pharmacies.

Why Are Some Patients Still Having Trouble?

Even for a widely available generic drug, several factors can cause localized supply interruptions:

Seasonal demand spikes. Spring pollen season (February–May) and fall ragweed season (August–October) drive significant increases in montelukast prescriptions. Pharmacy inventory doesn't always scale with demand.

Pediatric formulation scarcity. The 4 mg oral granule packets and 4 mg/5 mg chewable tablets are manufactured by fewer companies than the adult 10 mg tablet. When demand rises or a manufacturer has a production hiccup, pediatric formulations bear the brunt.

Generic supplier consolidation. While many companies manufacture montelukast, a given pharmacy typically sources from 1–2 preferred suppliers. Temporary production slowdowns at a preferred supplier ripple through to pharmacy-level shortages.

Formulary changes in January. When insurance plans switch their preferred generic manufacturer at the start of a plan year, pharmacy ordering cycles shift, sometimes causing short-term supply gaps in the transition period.

History of Montelukast Availability

Montelukast was first FDA-approved in 1998 as Singulair, manufactured exclusively by Merck. The patent expired in August 2012, and the FDA approved several generic versions the same day. This opened the market to dozens of manufacturers, dramatically increasing supply and reducing cost.

In March 2020, the FDA added a black box warning to montelukast due to neuropsychiatric side effects (depression, suicidal thoughts, behavioral changes). This resulted in some prescribers switching patients away from montelukast — particularly for isolated allergic rhinitis — but overall prescription volumes remain high, with approximately 9.3 million U.S. patients filling montelukast prescriptions annually.

Which Strengths and Forms Are Most Affected by Stock Gaps?

10 mg film-coated tablet (adults): Widely available; rarely out of stock

5 mg chewable tablet (children 6–14): Occasionally in limited supply at individual pharmacies

4 mg chewable tablet (children 2–5): Most likely to require calling multiple pharmacies

4 mg oral granule packets (infants 6 months+): Fewest manufacturers; highest likelihood of needing to search multiple pharmacies

What Should Patients Do Right Now?

If you're having difficulty filling your montelukast prescription, here are your best moves:

Don't just wait at your current pharmacy. Stock at a neighbor pharmacy may be completely different.

Use medfinder. medfinder calls pharmacies near you to find which ones can fill your prescription — and texts you the results.

Request a partial fill. Many pharmacies can dispense a partial supply (e.g., 10–15 days) while waiting for a restock.

Contact your prescriber if supply issues persist. They can help identify alternatives or bridge therapy if needed.

Consider switching to mail-order. Mail-order pharmacies like Express Scripts, CVS Caremark, or Amazon Pharmacy maintain larger inventory buffers and are ideal for 90-day supplies of a daily controller medication.

Should I Stop Taking Montelukast If I Run Out?

Do not stop montelukast for asthma without talking to your doctor first. While montelukast does not require a physical taper (there's no withdrawal syndrome in the traditional sense), stopping a controller medication abruptly can allow airway inflammation to return, leading to more frequent asthma symptoms and increased reliance on your rescue inhaler.

For allergic rhinitis, missing a few days of montelukast is less urgent, but symptoms may worsen. OTC antihistamines like cetirizine or loratadine can provide short-term symptom relief while you locate your prescription.

Use medfinder to find your prescription quickly, or read our guide to alternatives to montelukast for more options.