Plain-English fact sheet
Linaclotide
Also known as Linzess, guanylate cyclase-C agonist
Linaclotide acts locally in the intestine to increase fluid secretion and reduce constipation-related symptoms. Its evidence is strong for labeled gastrointestinal uses, not whole-body wellness.
Quick answer
Linaclotide is FDA approved as Linzess for specific forms of constipation and constipation-predominant irritable bowel syndrome in defined adult and pediatric age groups. It is not a systemic recovery, metabolic, or gut-healing peptide.
By the PeptideFactSheets Editorial Team. Claims are source-checked under our editorial policy; clinician review is identified only when a named reviewer is shown.
What is Linaclotide?
Linaclotide is a 14-amino-acid peptide that activates guanylate cyclase-C on the intestinal surface and is minimally absorbed into the bloodstream.
Its local action increases intestinal fluid and can change pain signaling, which is why evidence is tied to constipation outcomes.
Why are people interested in it?
It demonstrates that an oral peptide can work primarily at the gut surface without needing broad systemic exposure.
The same secretory mechanism that helps constipation also explains the main risk: diarrhea and dehydration.
Current regulatory status
Current FDA labeling covers IBS with constipation, chronic idiopathic constipation, and pediatric functional constipation in the specific age groups listed for each indication.
What is it approved for?
- The adult and age-specific pediatric constipation indications in current Linzess labeling
What is it being studied for?
Investigational areas
- Other carefully defined disorders of gut sensation and motility
Evidence snapshot
Multiple controlled trials and indication expansions support the labeled gastrointestinal uses. The peptide's local action and evidence do not establish general microbiome, anti-inflammatory, or wellness benefits.
Potential benefits being researched
- Phase 3 trials found improvements in bowel-frequency and abdominal-symptom endpoints compared with placebo.
- Pediatric trials supported selected age-specific label expansions rather than unrestricted use in children.
Potential does not mean proven. Study design, population, endpoint, and regulatory review matter.
Known or possible risks
- The label carries a boxed warning about serious dehydration risk in children younger than 2 years.
- Severe diarrhea can occur and is the main clinically important adverse effect.
- It is contraindicated when mechanical gastrointestinal obstruction is known or suspected.
What we still do not know
- Which patients will have a durable response rather than intolerable diarrhea
- Long-term comparative effectiveness across approved constipation medicines
- Whether newer formulations can separate pain relief from secretory effects
- Benefits outside labeled constipation disorders
Plain-English takeaway
Linaclotide is a well-studied local gut peptide for specific constipation disorders. It should not be stretched into a general claim about repairing or optimizing the gut.
Research and reference links
Use these primary and reputable sources to verify status and read beyond this summary. Trial registries may list studies without proving a benefit.
- 1FDA prescribing information: Linzess
Current age-specific indications, boxed warning, contraindications, and safety information.
- 2Randomized Phase 3 IBS-C trial
Controlled trial of abdominal pain and bowel outcomes with randomized withdrawal.
- 3Randomized pediatric functional-constipation trial
Age-specific Phase 3 evidence supporting a pediatric indication.