Is linaclotide effective?

Multiple phase-3 randomized trials and network meta-analyses show it significantly improves bowel movements and abdominal symptoms versus placebo.

What is the most common side effect?

Diarrhoea is the most common adverse effect and is dose-related; it can occasionally be severe enough to stop treatment.

Who should not take linaclotide?

It is contraindicated under an FDA boxed warning in children under 2 years and in anyone with known or suspected mechanical bowel obstruction.

EMA-approvedaka Linzess, Constella

Linaclotide — Complete Research Guide (2026)

Q: How does linaclotide work?

It activates guanylate cyclase-C receptors in the gut, increasing fluid secretion to speed transit and reducing visceral pain signalling.

Last updated 2026-06-30

TL;DR

Linaclotide (also known as Linzess) is a peptide catalogued under Gastrointestinal (Guanylate cyclase-C agonist). It is described as: GC-C receptor. Documented context: IBS-C; chronic idiopathic constipation. Neutral reference entry; EU status: EU-approved prescription medicine.

What is Linaclotide?

Linaclotide (brand names Linzess in the US and Constella in Europe) is a 14-amino-acid guanylate cyclase-C (GC-C) receptor agonist peptide, approved by the FDA and EMA for irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation (CIC) in adults, and in the US also for functional constipation in children aged 6-17.

Its efficacy is well established through multiple large phase-3 randomized controlled trials and independent network meta-analyses, placing it among the best-evidenced prescription secretagogues.

This is informational content about an approved medicine and is not medical advice.

How does Linaclotide work?

Linaclotide binds and activates guanylate cyclase-C on the luminal surface of intestinal cells, raising cyclic GMP, which increases secretion of chloride and bicarbonate into the gut lumen and accelerates transit.

The rise in extracellular cyclic GMP also dampens pain-sensing afferent nerves, which is thought to reduce the abdominal pain of IBS-C. [INFOGRAPHIC: Linaclotide guanylate cyclase-C activation]

What does the research say about Linaclotide?

In two 12-week phase-3 chronic-constipation trials (n=1276), roughly 16-21% of linaclotide patients were complete spontaneous bowel movement responders versus about 3-6% on placebo. ^[1]
In a 12-week IBS-C trial, about 34% of linaclotide 290 ug patients met the FDA abdominal-pain plus complete-spontaneous-bowel-movement responder endpoint versus about 14% on placebo. ^[3]
In a network meta-analysis of secretagogues for IBS-C, linaclotide 290 ug once daily ranked first for the FDA-recommended composite responder endpoint. ^[4]

Clinical research & studies

The references below are the primary sources cited throughout this guide. Each links directly to PubMed or the regulator. Where evidence is preclinical (animal or in-vitro), that is stated rather than implied.

[1] Two randomized trials of linaclotide for chronic constipation — Lembo AJ et al., N Engl J Med 2011. (RCT n=1276 (two phase-3 trials))
[2] Linaclotide for irritable bowel syndrome with constipation: a 26-week, randomized, double-blind, placebo-controlled trial to evaluate efficacy and safety — Chey WD et al., Am J Gastroenterol 2012. (RCT (26-week phase 3))
[3] A 12-week, randomized, controlled trial with a 4-week randomized withdrawal period to evaluate the efficacy and safety of linaclotide in irritable bowel syndrome with constipation — Rao S et al., Am J Gastroenterol 2012. (RCT (12-week phase 3 with randomized withdrawal))
[4] Efficacy of Secretagogues in Patients With Irritable Bowel Syndrome With Constipation: Systematic Review and Network Meta-analysis — Black CJ et al., Gastroenterology 2018. (systematic review / network meta-analysis)
[5] Efficacy of drugs in chronic idiopathic constipation: a systematic review and network meta-analysis — Luthra P et al., Lancet Gastroenterol Hepatol 2019. (systematic review / network meta-analysis)

Dosing context

This is not medical advice or a usage recommendation. Dosing figures are reported research context only, cited from the published literature.

Approved oral products are taken once daily on an empty stomach at least 30 minutes before the first meal, at 290 ug for IBS-C and 72 or 145 ug for chronic idiopathic constipation in adults.

These are regulator-approved product parameters described for context only and are not a personal treatment recommendation.

Side effects & safety profile

The most common adverse effect is dose-related diarrhoea (roughly 16-20% versus about 5% on placebo), which can occasionally be severe and lead to discontinuation; bloating, abdominal pain and flatulence also occur.

Linaclotide carries an FDA boxed warning: it is contraindicated in patients under 2 years of age because it caused fatal dehydration in neonatal mice, and it is contraindicated in patients with known or suspected mechanical gastrointestinal obstruction.

Stacking & combinations

There is no established evidence base for combining linaclotide with other peptides; it is used as a stand-alone prescription therapy under medical supervision.

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Frequently asked questions

It is an FDA- and EMA-approved prescription drug for irritable bowel syndrome with constipation (IBS-C) and chronic idiopathic constipation in adults, sold as Linzess and Constella.

References

[1] Two randomized trials of linaclotide for chronic constipation — Lembo AJ et al., N Engl J Med 2011. PMID: 21830967. View sourceStudy: RCT n=1276 (two phase-3 trials)Linaclotide significantly increased complete spontaneous bowel movements versus placebo in chronic constipation.
[2] Linaclotide for irritable bowel syndrome with constipation: a 26-week, randomized, double-blind, placebo-controlled trial to evaluate efficacy and safety — Chey WD et al., Am J Gastroenterol 2012. PMID: 22986437. View sourceStudy: RCT (26-week phase 3)Linaclotide 290 ug significantly improved abdominal pain and bowel symptoms in IBS-C versus placebo over 26 weeks.
[3] A 12-week, randomized, controlled trial with a 4-week randomized withdrawal period to evaluate the efficacy and safety of linaclotide in irritable bowel syndrome with constipation — Rao S et al., Am J Gastroenterol 2012. PMID: 22986440. View sourceStudy: RCT (12-week phase 3 with randomized withdrawal)Linaclotide 290 ug significantly improved the FDA composite responder endpoint versus placebo in IBS-C.
[4] Efficacy of Secretagogues in Patients With Irritable Bowel Syndrome With Constipation: Systematic Review and Network Meta-analysis — Black CJ et al., Gastroenterology 2018. PMID: 30144426. View sourceStudy: systematic review / network meta-analysisLinaclotide 290 ug once daily ranked first among secretagogues for the FDA-recommended IBS-C endpoint.
[5] Efficacy of drugs in chronic idiopathic constipation: a systematic review and network meta-analysis — Luthra P et al., Lancet Gastroenterol Hepatol 2019. PMID: 31474542. View sourceStudy: systematic review / network meta-analysisIn chronic idiopathic constipation, linaclotide was among the efficacious secretagogues, though prucalopride ranked first at 12 weeks.

This article is for educational and research purposes only. Peptides discussed here are not approved for human consumption by the FDA, EMA, or equivalent regulators outside of specific clinical contexts. Always consult a licensed medical professional before any therapeutic use.