Why Is Pentasa XR So Hard to Find? [Explained for 2026]

If you've recently tried to fill a Pentasa XR prescription and been told it's out of stock, you're not imagining things. As of early 2026, mesalamine extended-release capsules — the active ingredient in Pentasa XR — are facing a genuine supply disruption affecting patients across the United States. In this article, we'll break down exactly what's happening, why the shortage occurred, and what steps you can take today to get your medication.

Is There an Official Pentasa XR Shortage in 2026?

Yes. The American Society of Health-System Pharmacists (ASHP) officially tracks mesalamine extended-release capsules as a current shortage. As of March 2026, Sun Pharmaceutical Industries — one of the major generic manufacturers of 500 mg mesalamine ER capsules — has placed the product on back order with no estimated resupply date. The ASHP shortage bulletin was created in January 2026 and has been updated as recently as March 24, 2026.

The brand-name product, Pentasa (manufactured by Takeda Pharmaceuticals), may still be available at some pharmacies, but many insurance plans don't cover the brand when a generic is supposed to exist. If the generic is backordered and your insurance requires it, you're caught in a frustrating gap.

What Is Pentasa XR and Who Needs It?

Pentasa XR is a brand name for mesalamine extended-release capsules, an aminosalicylate medication used to treat mild to moderately active ulcerative colitis (UC) in adults. Unlike some other mesalamine formulations that only target the colon, Pentasa's controlled-release mechanism releases the drug continuously throughout the entire gastrointestinal tract — from the small intestine through the colon. This makes it a preferred option for patients with UC that extends into the small bowel.

The standard dose is 1 gram (either four 250 mg capsules or two 500 mg capsules) taken four times daily, for a total of 4 grams per day. Because it requires multiple daily doses, patients depend on a steady, reliable supply — making any shortage particularly disruptive for people managing a chronic condition.

Why Is Pentasa XR So Hard to Find Right Now?

Several overlapping factors are driving the current shortage of Pentasa XR and its generic equivalent, mesalamine ER:

• Manufacturing back order: Sun Pharma, a key generic manufacturer, has placed the 500 mg capsule on back order with no known return date. When a major supplier drops out, independent pharmacies and small chains often exhaust their remaining stock quickly.
• Raw material sourcing challenges: Mesalamine manufacturing requires specific active pharmaceutical ingredients (APIs) that can be difficult to source consistently. Global supply chain disruptions have impacted multiple drug manufacturers over the past few years.
• Consolidation of generic manufacturers: When a drug has only a handful of approved generic manufacturers, any production slowdown at one company ripples across the entire market.
• Insurance and formulary issues: Many insurance plans require generic mesalamine ER before covering the brand. If the generic is unavailable, prior authorization processes can delay access to the brand, making it feel like a shortage even when Pentasa brand exists.
• Pharmacy inventory variability: Even when Pentasa XR is technically available in the market, individual pharmacy locations may not have it in stock. Large chain pharmacies prioritize high-volume medications; specialty or independent pharmacies often have more flexibility to stock or order lower-volume drugs.

How Long Has Pentasa XR Been in Shortage?

The current ASHP shortage bulletin for mesalamine extended-release capsules was created in January 2026. However, patients and pharmacists have reported sporadic availability issues with Pentasa and its generic for longer than that, as the drug occupies a somewhat niche position in the ulcerative colitis market. Generic competition has actually worsened this in some ways: with Pentasa's annual U.S. sales around $213 million as of 2022 (per IQVIA Health data), the entry of generics fragmented the market and shifted manufacturer focus, sometimes leaving gaps.

Who Is Most Affected by the Pentasa XR Shortage?

Patients most impacted by the current shortage include:

• Adults with mild-to-moderate ulcerative colitis who depend on Pentasa XR as part of their maintenance regimen
• Patients whose UC extends into the small intestine, making Pentasa's GI-tract-wide release particularly important
• Patients on insurance plans that require prior authorization before covering brand-name Pentasa
• Patients in rural areas with fewer pharmacy options to check

What Can You Do If You Can't Find Pentasa XR?

You have several concrete options right now:

1. Use medfinder: medfinder.com calls pharmacies near you to find which ones have Pentasa XR in stock, saving you hours of phone calls.
2. Call independent pharmacies: Independent and compounding pharmacies often carry or can special-order medications that chain pharmacies don't stock.
3. Ask about the 250 mg capsule: The current shortage primarily affects the 500 mg capsule. If you normally take 500 mg capsules, ask your pharmacist if 250 mg capsules are available — you'd just take two capsules to achieve the same dose.
4. Talk to your doctor about alternatives: Other mesalamine formulations like Lialda or Apriso target the colon and may be appropriate for your situation. See our guide: Alternatives to Pentasa XR if you can't fill your prescription
5. Ask about prior authorization for brand Pentasa: If the generic is unavailable and you need the brand, your doctor can submit a prior authorization to your insurance documenting the shortage.

Is the Pentasa XR Shortage Going to Get Better?

As of the most recent ASHP update in March 2026, no estimated resupply date has been provided by Sun Pharma. That means patients and providers should plan on this shortage continuing for the foreseeable future. The good news is that the brand-name Pentasa and the 250 mg capsule formulation may offer alternative paths to treatment in the meantime.

Ultimately, the best strategy is to be proactive. Don't wait until you run out of your current supply to start looking. Begin exploring alternatives and pharmacy options with at least two to three weeks to spare, and work with your gastroenterologist or prescriber to have a backup plan in place.

The Bottom Line

Pentasa XR is genuinely hard to find in 2026 due to an active manufacturing back order affecting major generic suppliers. The shortage is real, officially tracked by ASHP, and has no estimated end date. The fastest path forward is to expand your pharmacy search and explore therapeutic alternatives. For a step-by-step approach, check out: How to find Pentasa XR in stock near you