Linaclotide
Also known as: Linzess, Constella, MD-1100
Linaclotide is a minimally absorbed oral peptide for selected constipation disorders. Local intestinal GC-C activation increases fluid secretion, with severe diarrhea and strict pediatric age boundaries among its key safety considerations.
Quick Facts
An oral, locally acting peptide
Linaclotide is a 14-amino-acid peptide, marketed as Linzess and as Constella in some regions. Developed as MD-1100, it was first approved in the United States in 2012. It remains predominantly within the intestine rather than producing meaningful systemic absorption.
GC-C signaling, stool passage and abdominal pain
Activation of guanylate cyclase-C on intestinal lining cells raises cyclic GMP. This opens chloride and bicarbonate channels, increasing luminal fluid, softening stool and accelerating transit. Extracellular cyclic GMP may also reduce gut-wall pain-nerve sensitivity, helping explain IBS-C abdominal-pain findings. The local gut action is important to interpreting the mechanism.
In the Phase 3 IBS-C program, approximately one-third of patients met the combined FDA responder endpoint, compared with about 14% of placebo recipients.
Supporting references: endpoint.
Sources: [1]
Indications and ages
| Indication | Population | Approval context |
|---|---|---|
| IBS with constipation | Adults | Initial 2012 approval |
| Chronic idiopathic constipation | Adults | Initial 2012 approval |
| IBS with constipation | Children 7 years and older | Later extension |
| Functional constipation | Children 2 years and older | Later extension |
Supporting references: approved.
Sources: [2]
Use and timing
The product is taken once daily on an empty stomach for the indicated constipation disorder. It must not be used in children younger than 2 years. Its boxed warning follows deaths from severe dehydration in very young animals and is not a general pediatric authorization.
Diarrhea, dehydration and obstruction
Diarrhea is the most common reason for discontinuation. Abdominal pain, gas and bloating are also reported. Severe diarrhea can produce dehydration. Children under 2 years and people with known or suspected bowel obstruction are contraindicated populations.
References and further reading
This reference draws on Superpower’s Peptide Library and the research linked below. Peptide Dossier’s editorial team adapted and integrated the material on .
- 10.1038/ajg.2012.254GC-C signaling, stool passage and abdominal painCited in: GC-C signaling, stool passage and abdominal pain
- rxabbvie.comIndications and agesCited in: Indications and ages
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Disclaimer: This article is for informational and educational purposes only. It is not intended as medical advice. The information presented is based on published research and should not be used as a substitute for professional medical guidance. Always consult a qualified healthcare provider before starting any peptide protocol. Some peptides discussed may not be approved for human use by the FDA or equivalent regulatory bodies.