Ironwood's LINZESS Gains FDA Approval for Functional Constipation

Ironwood Pharmaceuticals Inc. (NASDAQ: IRWD) said on May 27, 2026, that the U.S. Food and Drug Administration approved its drug LINZESS for treating functional constipation. The decision expands the label of the guanylate cyclase-C agonist, offering a new therapy option for patients. The approval stems from clinical trials that demonstrated the drug’s safety and efficacy in the patient group. LINZESS is already widely prescribed for adults with irritable bowel syndrome with constipation and chronic idiopathic constipation. Ironwood shares U.S. profits equally with partner AbbVie Inc. (NYSE: ABBV), which markets the drug. In 2025, LINZESS generated $1.2 billion in U.S. net sales, making it a key revenue driver. The new indication could unlock additional growth by tapping an underserved market segment, boosting Ironwood’s earnings as it books its 50% share of the incremental profit.