What Is Linzess? Uses, Dosage, and What You Need to Know in 2026

Linzess is a prescription medication used to treat certain types of chronic constipation and irritable bowel syndrome. If you've been prescribed it—or are wondering if it might be right for you—here's a comprehensive overview of what Linzess is, how it works, who it's approved for, and what to expect.

What Is Linzess?

Linzess is the brand name for linaclotide, a prescription oral capsule belonging to a drug class called guanylate cyclase-C (GC-C) agonists. It was first FDA-approved in August 2012 and is manufactured by AbbVie in partnership with Ironwood Pharmaceuticals. Linzess is available in three strengths: 72 mcg, 145 mcg, and 290 mcg.

Unlike traditional laxatives, which work by drawing water into the bowel or stimulating gut movement, Linzess activates specific receptors in the intestinal lining to increase fluid secretion and help regulate bowel function. It is taken once daily on an empty stomach, at least 30 minutes before the first meal of the day.

What Is Linzess Approved to Treat?

Linzess has three FDA-approved indications:

1. Irritable Bowel Syndrome with Constipation (IBS-C): In adults and pediatric patients 7 years and older. IBS-C causes recurring abdominal pain or discomfort along with constipation. Linzess helps relieve both the constipation and the associated pain.
2. Chronic Idiopathic Constipation (CIC): In adults. "Idiopathic" means there is no identifiable underlying medical cause. CIC is characterized by infrequent, hard, or difficult-to-pass stools lasting 3 months or more.
3. Functional Constipation (FC): In pediatric patients 2 years and older. Functional constipation in children is not caused by a specific disease and involves difficulty passing stools despite normal anatomy.

How Does Linzess Work?

Linzess works by binding to and activating guanylate cyclase-C (GC-C) receptors on the surface of intestinal cells. This increases a molecule called cyclic GMP (cGMP) inside intestinal cells, which in turn triggers the secretion of chloride and bicarbonate ions—and water follows. The result: more fluid in the intestine, softer stools, and faster transit. It also reduces pain signaling in the gut. For a deeper explanation, see our article on how Linzess works.

Linzess Dosage Information

The recommended dose depends on the condition being treated and the patient's age:

• IBS-C in adults: 290 mcg once daily (or 145 mcg if the standard dose causes intolerable side effects)
• CIC in adults: 145 mcg once daily (72 mcg may be used based on individual presentation or tolerability)
• IBS-C in children 7–17: 145 mcg or 290 mcg once daily as directed by prescriber
• FC in children 6–17: 72 mcg once daily

Always take Linzess in the morning on an empty stomach, at least 30 minutes before your first meal. Swallow capsules whole. If you can't swallow capsules, you may open them and sprinkle the beads into a teaspoon of applesauce or 1 ounce (30 mL) of room-temperature bottled water and swallow immediately—do not chew the beads.

Important Safety Information

Linzess carries important warnings:

• Not for children under 2: Linzess can cause fatal dehydration in children under 2 years old. Keep it locked away from young children.
• Diarrhea is common: The most frequent side effect. If severe diarrhea develops, stop taking Linzess and contact your doctor.
• Bowel obstruction: Do not take Linzess if you have a bowel obstruction.
• Negligible systemic absorption: Linzess works locally in the gut and is not significantly absorbed into the bloodstream. This is why it has virtually no drug-drug interactions.

How Long Does Linzess Take to Work?

Most patients start to experience constipation relief within about 1 week of starting Linzess. For patients with IBS-C, abdominal symptoms such as pain, discomfort, and bloating may continue improving over the next 3 months of treatment. Linzess is designed for long-term daily use—it is not an as-needed or rescue laxative.

Where to Fill Your Linzess Prescription

Because Linzess is brand-name only with no generic (until at least 2029), some pharmacies don't stock it regularly. If you're having trouble filling your prescription, use medfinder to locate a pharmacy near you that has it in stock. For cost-saving options, including the manufacturer savings card (as low as $30/month with commercial insurance), see our savings guide.