Evidence memo / Tissue repair & recovery

Linaclotide

Also: Linzess · Constella

Linaclotide (Linzess) is a guanylate cyclase-C agonist peptide approved for irritable bowel syndrome with constipation and chronic idiopathic constipation in adults, and for functional constipation in children 6 to 17. It works locally in the gut and is minimally absorbed. The approved uses are well established. The Watchlist boundary is keeping it to its approved gastrointestinal indications and noting the contraindication in very young children.

Approved for specific usesPost-market evidenceSafety / regulatory watch

The verdict

Our read at a glance.

Whether linaclotide's approved constipation and IBS-C benefits are understood within those specific gut indications, rather than generalized to broader gut-health claims.

The signal
Randomized trials support linaclotide for reducing constipation and abdominal symptoms in IBS-C and chronic idiopathic constipation, and a pediatric trial supported its use in functional constipation in children 6 to 17. Diarrhea is the most common side effect.
The unknown
Long-term symptom durability and how it compares head to head with other secretagogues and standard laxatives across different patients.
Our read
A proven, gut-specific prescription drug for constipation and IBS-C. Linaclotide works locally and is well studied for its approved uses, so the main point is to keep it to those indications and respect the pediatric contraindication.

The mechanism

How it works.

Linaclotide is a 14-amino-acid peptide that activates guanylate cyclase-C, a receptor on the inner surface of the intestinal lining. Switching it on raises cGMP inside those cells, which pushes chloride and bicarbonate into the gut, pulling water in behind them so stool softens and moves faster. The same cGMP signal is thought to dampen pain-sensing nerves in the gut wall, which helps explain the relief of abdominal pain in IBS-C. The peptide is barely absorbed into the bloodstream, so its action stays local to the intestine.

Safety & regulatory boundary

The consequential part.

Linaclotide carries a boxed warning and is contraindicated in patients under 2 years of age because of a risk of serious dehydration shown in young animals, and it is approved only for specific gastrointestinal indications. Linzess is the approved product and is not the same as compounded or research-labeled linaclotide, and the approved use does not extend to general wellness or detox claims.

What's next

What we're watching.

Pediatric safety and efficacy data, comparative effectiveness against other constipation treatments, and any new indications.

Context

Why this is discussed.

Linaclotide is a commonly prescribed prescription option for chronic constipation and IBS-C, so it comes up in discussions of gut-acting peptides.

The evidence base

21 cited references.

Regulatory & labels1

DailyMed label: Linzess

Allergan, Inc. (FDA label) · 2025

Registered trials8

Proof of Principle Study for an Efficacy Trial of Linaclotide for Cystic Fibrosis

ClinicalTrials.gov · EARLY_PHASE1 · RECRUITING · 2026-03-09

GCC Agonist Signal in the Small Intestine

ClinicalTrials.gov · PHASE1 · COMPLETED · 2022-11-30

Efficacy of Linaclotide in Type II Diabetics With Chronic Constipation

ClinicalTrials.gov · PHASE4 · ACTIVE_NOT_RECRUITING · 2015-09-01

Linaclotide in Treating Patients With Stages 0-3 Colorectal Cancer

ClinicalTrials.gov · PHASE2 · ACTIVE_NOT_RECRUITING · 2019-10-30

"Efficacy and Safety of Linaclotide in Chronic Constipation"

ClinicalTrials.gov · PHASE4 · NOT_YET_RECRUITING · 2026-02-20

Linaclotide for Colonoscopy Bowel Prep

ClinicalTrials.gov · PHASE1/PHASE2 · RECRUITING · 2025-12-01

A Study of Virtual Reality and Linaclotide for IBS-C

ClinicalTrials.gov · NA · RECRUITING · 2024-05-31

Indexed literature (PubMed)12

Irritable bowel syndrome

Sebastián Domingo JJ · Med Clin (Barc) · 2022

Recent advances in the treatment of irritable bowel syndrome

Bonetto S et al. · Pol Arch Intern Med · 2021

Diagnosis and management of chronic constipation in adults

Rao SS et al. · Nat Rev Gastroenterol Hepatol · 2016

Linaclotide

PubMed · 2006

Keep reading

Related published memos.