Linaclotide
Aliases: Linzess · Constella
Last verified: 2026-09-23
The short version
A 14-aa peptide — guanylate cyclase-C agonist in the gut; approved for IBS-C and chronic constipation. Acts locally (minimal absorption).
Identity & type
- Molecular type
- peptide
- Origin
- A 14-aa peptide — guanylate cyclase-C agonist in the gut; approved for IBS-C and chronic constipation.
Mechanism of action
GC-C activation → cGMP → intestinal fluid secretion + reduced visceral pain.
Dosing & routes
Official / clinical context
Approved drug — indications, dosing and warnings are defined by the official label. 145–290 mcg orally daily on empty stomach.
Regulator-approved labeling and published study designs — never a recommendation.
Community-reported practice
145–290 mcg orally daily on empty stomach. Linzess: in IBS-C/chronic constipation — regular bowel movements and less bloating in most; diarrhea is the most common side effect.
Unverified self-reports. Not medical advice. Not endorsement.
Expected effects (community)
Linzess: in IBS-C/chronic constipation — regular bowel movements and less bloating in most; diarrhea is the most common side effect.
Protocol — official vs community
Official / label
Linzess/Constella: chronic idiopathic constipation (CIC) — 145 mcg orally once daily (may increase to 290 mcg); irritable bowel syndrome with constipation (IBS-C) — 290 mcg once daily; pediatric IBS-C (≥6 years in US label) — weight-based lower dose. Taken at least 30 minutes before the first meal, on an empty stomach.
- 01CIC: 145 mcg daily → 290 mcg daily if response inadequate and tolerated
Duration: Chronic while indicated; stop if no response after an adequate trial (4 weeks per label guidance).
Luminal GC-C agonism — minimal systemic absorption, which is why it is usable long-term. Diarrhea is the dominant adverse effect and the usual dose limiter.
Community (anecdotal)
Taken exactly per label (it is a cheap generic Rx); no community modification of substance.
- Cycle:
- Continuous.
- Break:
- None by design.
Community discussion is ordinary patient experience-sharing, not protocol innovation; 'empty-stomach timing' is the one detail users rediscover constantly.
Human evidence
Phase III programs for IBS-C/CC; long-term safe.
Preclinical evidence
The preclinical phase was completed and submitted to regulators as part of registration; pharmacology and toxicology details are part of the official label.
Known risks
- Diarrhea (most common), bloating.characterized
Teal: characterized in clinical/labeling contexts. Amber: theoretical or reported outside controlled settings.
Unknowns & evidence gaps
- Real-world data outside controlled trials