Comprehensive medication guide to Mesalamine XR including estimated pricing, availability information, side effects, and how to find it in stock at your local pharmacy.
Estimated Insurance Pricing
$0–$30 copay for generic mesalamine ER on most commercial plans (Tier 1–2); brand-name formulations may require prior authorization and higher copays; manufacturer savings card for Apriso may reduce cost to $0–$10 for eligible commercially insured patients.
Estimated Cash Pricing
$450–$560 retail for generic 500 mg ER capsules (120 count); as low as $37–$45 with GoodRx or SingleCare discount cards. Brand-name Apriso or Pentasa runs $500–$700/month without assistance.
Medfinder Findability Score
38/100
Summarize with AI
On this page
Mesalamine XR is the extended-release formulation of mesalamine, also known as 5-aminosalicylic acid (5-ASA) or mesalazine. It is an aminosalicylate medication used primarily to treat and maintain remission of mild to moderately active ulcerative colitis (UC) in adults. Mesalamine works locally in the intestinal lining to reduce inflammation without suppressing the immune system.
Brand names for mesalamine extended-release capsules include Pentasa (250 mg and 500 mg, by Takeda Pharmaceuticals) and Apriso (0.375 g, by Salix Pharmaceuticals/Bausch Health). Generic versions from multiple manufacturers are also available. Mesalamine first gained FDA approval in December 1987, and the extended-release capsule formulation has been widely used since the early 1990s.
Approximately 600,000–900,000 Americans live with ulcerative colitis, and mesalamine is often the first medication prescribed for mild-to-moderate disease. Annual U.S. sales of mesalamine formulations run into the hundreds of millions of dollars, reflecting its importance as a cornerstone treatment for IBD patients.
We have a 99% success rate finding medications, even during nationwide shortages.
Need this medication?
Mesalamine XR works by acting locally within the intestinal lining to reduce inflammation. Its exact mechanism is not fully understood, but it is believed to inhibit the cyclooxygenase (COX) and lipoxygenase (LOX) enzyme pathways that produce prostaglandins and leukotrienes — inflammatory chemicals that are overproduced in ulcerative colitis. By blocking these pathways, mesalamine reduces the production of these mediators and calms the inflammatory response in the colon.
Mesalamine also modulates inflammatory cytokine activity and acts as an antioxidant, scavenging free radicals in the inflamed intestinal tissue. Unlike biologics or immunomodulators, mesalamine does NOT suppress the immune system — it acts locally at the site of inflammation, which is why it has a favorable safety profile for long-term use.
The extended-release (XR) formulation uses precision polymer coatings (ethylcellulose-based granules) that resist dissolving until the capsule is further along in the GI tract. This ensures the drug is gradually released from the upper small intestine through the colon, maximizing the amount reaching inflamed tissue. Clinical studies show 80% of patients on 4–6 g/day achieve significant improvement within 4 weeks.
0.375 g — extended-release capsule
Apriso strength; 1.5 g (4 capsules) once daily in the morning for maintenance of remission
250 mg — extended-release capsule
Pentasa strength; used in multi-dose regimens for treatment of active UC
500 mg — extended-release capsule
Pentasa/generic strength; 1 g (2 capsules) four times daily for treatment of active UC (4 g/day total)
Finding Mesalamine XR can be challenging in 2026. As of March 2026, the ASHP has confirmed that Sun Pharmaceutical Industries' mesalamine extended-release 500 mg capsules are on back order with no estimated resupply date. This affects a significant portion of the generic mesalamine ER supply in the U.S.
Brand-name Apriso (0.375 g) and Pentasa are not on the FDA's active shortage list, but patients still frequently report localized pharmacy availability issues. Chain pharmacies often stock limited quantities, and automated inventory systems can create gaps when multiple patients refill at the same time. Mesalamine XR is a complex product to manufacture with a limited number of suppliers, making it more vulnerable to supply disruptions.
If you're struggling to find Mesalamine XR, medfinder can help. Enter your medication, dosage, and ZIP code, and medfinder contacts pharmacies in your area to find which ones can currently fill your prescription — texting results back to you.
Mesalamine XR is not a controlled substance, so it can be prescribed by any licensed prescriber in the United States. There are no DEA scheduling restrictions on who can write this prescription or how many refills can be provided.
Prescribers who commonly manage mesalamine therapy include:
Gastroenterologists (most common for UC diagnosis and complex management)
Primary care physicians (PCPs) for maintenance management in established UC patients
Internists and general practitioners
Nurse practitioners (NPs) and physician assistants (PAs) with prescribing authority
Colorectal surgeons (for post-surgical IBD management, off-label use in Crohn's)
Mesalamine XR is fully available via telehealth in all states, as it is not a controlled substance. Many gastroenterologists and PCPs now offer virtual visits for UC management, refills, and prescription adjustments — a convenient option for patients who need guidance during the current supply shortage.
No. Mesalamine XR is not a controlled substance and is not scheduled under the DEA (Drug Enforcement Administration). It has no abuse potential, does not produce dependence, and is not subject to the same prescribing restrictions as controlled medications.
Because mesalamine is not controlled, it can be prescribed by any licensed healthcare provider including nurse practitioners (NPs) and physician assistants (PAs) in most states. It can also be prescribed via telehealth in all states without the restrictions that apply to controlled substances. Refills can be written without in-person visits in most circumstances, making it convenient for long-term maintenance therapy.
Mesalamine XR is generally well-tolerated. The most commonly reported side effects (incidence ≥1–3% in clinical trials) include:
Headache
Nausea and vomiting
Diarrhea
Abdominal pain or cramping
Nasopharyngitis (runny nose, cold-like symptoms)
Flu-like illness
Sun sensitivity (increased sunburn risk)
Mesalamine-induced acute intolerance syndrome: cramping, bloody diarrhea, fever, headache, rash mimicking a UC flare (occurs in ~3% of patients)
Kidney damage (nephrotoxicity): interstitial nephritis, changes in urination, leg swelling; requires renal monitoring
Heart inflammation: myocarditis and pericarditis (rare); chest pain, shortness of breath
Blood dyscrasias: leukopenia, agranulocytosis, aplastic anemia; higher risk in elderly and with azathioprine/6-MP
Liver problems: hepatotoxicity, jaundice; rare but serious
Severe allergic reactions: hives, difficulty breathing, swelling of face/lips/tongue (especially in aspirin-allergic patients)
Know what you need? Skip the search.
Lialda (mesalamine DR 1.2 g tablets)
Delayed-release mesalamine tablet; once-daily dosing; approved for induction and maintenance in adults and children; often more available than XR capsules in 2026
Balsalazide (Colazal)
Aminosalicylate prodrug converted to mesalamine in the colon; for mild-to-moderate active UC; different chemical structure but same mechanism
Sulfasalazine (Azulfidine)
Original 5-ASA drug; effective and significantly less expensive; higher rate of side effects in some patients; widely available
Olsalazine (Dipentum)
Another 5-ASA prodrug for maintenance of remission in UC; less commonly used than mesalamine formulations
Prefer Mesalamine XR? We can find it.
NSAIDs (ibuprofen, aspirin, naproxen)
moderateAdditive nephrotoxicity risk; avoid concurrent use when possible; monitor kidney function if combination is necessary
Azathioprine / 6-Mercaptopurine
moderateMesalamine increases active metabolites of azathioprine, raising risk of blood dyscrasias; requires regular CBC monitoring
Proton pump inhibitors (omeprazole, pantoprazole)
minorMay increase GI pH and cause premature release of ER coating, reducing efficacy
Varicella vaccine
majorSalicylate-related compound increases theoretical risk of Reye syndrome with live vaccines
Warfarin / anticoagulants
moderateMay affect anticoagulation; monitor INR closely when initiating, stopping, or changing mesalamine dose
Antacids
minorMay alter GI pH and affect extended-release coating dissolution; avoid taking at the same time
Nephrotoxic drugs (aminoglycosides, cyclosporine, tacrolimus)
moderateAdditive nephrotoxicity risk; monitor renal function closely with concurrent use
Mesalamine XR is a cornerstone treatment for ulcerative colitis that has been in use for decades with a well-established safety and efficacy profile. Its local mechanism of action, lack of systemic immunosuppression, and multiple available formulations make it a versatile first-line option for mild-to-moderate UC. For the majority of patients, it is effective, well-tolerated, and affordable — especially with generic options and discount programs.
The primary challenge for patients in 2026 is availability — the ASHP-confirmed back order on Sun Pharma's 500 mg ER capsules has created real-world access gaps. Understanding your options (alternative formulations, independent pharmacies, mail-order) and working closely with your prescriber are the keys to maintaining treatment continuity.
If you're having trouble finding Mesalamine XR at your pharmacy, medfinder is here to help. Tell us your medication, dosage, and ZIP code, and we'll find pharmacies near you that can fill your prescription — so you can stay on your therapy without interruption.
Medfinder Editorial Standards
Our medication guides are researched and written to help patients make informed decisions. All content is reviewed for accuracy and updated regularly. Learn more about our standards
ChatGPT
Claude
Perplexity
Grok
Gemini