Linaclotide
Also known as: Linzess
Linaclotide is a guanylate cyclase-C receptor agonist that increases intestinal fluid secretion and accelerates colonic transit while reducing visceral pain. This synthetic peptide treats irritable bowel syndrome with constipation and chronic idiopathic constipation by activating cyclic GMP pathways in intestinal epithelial cells.
Linaclotide is a 1526.7 g/mol research peptide. Linaclotide is a guanylate cyclase-C receptor agonist that increases intestinal fluid secretion and accelerates colonic transit while reducing visceral pain. This synthetic peptide treats irritable bowel syndrome with constipation and chronic idiopathic constipation by activating cyclic GMP pathways in intestinal epithelial cells.
Also called: Linzess
1526.7 g/mol
Molecular Weight
Daltons
4
Strong Evidence
benefits
4
Studies Cited
peer-reviewed
145-290
Typical Dose
mcg
Overview
Linaclotide represents a breakthrough in gastrointestinal therapeutics, functioning as a selective guanylate cyclase-C (GC-C) receptor agonist that mimics endogenous guanylin and uroguanylin peptides. The compound binds to GC-C receptors on the luminal surface of intestinal epithelial cells, triggering a cascade that increases intracellular and extracellular cyclic guanosine monophosphate (cGMP) levels. This mechanism produces two primary therapeutic effects: enhanced chloride and bicarbonate secretion into the intestinal lumen, which increases fluid content and accelerates transit, and reduced transmission of pain signals from visceral afferent neurons through cGMP-dependent pathways. The peptide undergoes minimal systemic absorption, with its therapeutic effects occurring primarily within the gastrointestinal tract. Clinical studies demonstrate significant improvements in bowel movement frequency, stool consistency, and abdominal pain scores in patients with constipation-predominant disorders. Research applications focus on understanding GC-C receptor signaling, intestinal fluid regulation, and visceral pain mechanisms.
Key Takeaways: Linaclotide
- Strongest evidence supports Linaclotide for accelerated colonic transit and improved stool consistency
- Research doses typically range from 145 to 290 mcg via oral
- 4 benefits with strong evidence, 2 moderate, 0 preliminary
- Half-life: Not applicable (minimal systemic absorption)
- 4 cited research studies in this guide
Mechanism of Action
Linaclotide binds to guanylate cyclase-C receptors on intestinal epithelial cells, increasing intracellular cGMP production. This activates the cystic fibrosis transmembrane conductance regulator (CFTR), promoting chloride and bicarbonate secretion into the intestinal lumen. Elevated extracellular cGMP also reduces visceral pain signaling by modulating pain-sensing neurons in the submucosal and myenteric plexuses.
Research Benefits
Linaclotide at a Glance
Linaclotide binds to guanylate cyclase-C receptors on intestinal epithelial cells, increasing intracellular cGMP production.
Accelerated Colonic Transit
Strong EvidenceIncreases bowel movement frequency by 1-3 movements per week through enhanced fluid secretion and smooth muscle stimulation via cGMP-mediated pathways.
Improved Stool Consistency
Strong EvidenceSoftens stool through increased water content in the colon, with 60-70% of patients achieving normal Bristol Stool Scale scores (types 3-5).
Visceral Pain Reduction
Strong EvidenceDecreases abdominal pain and discomfort scores by 30-40% through cGMP-mediated inhibition of nociceptive signaling in enteric neurons.
Enhanced Intestinal Secretion
Strong EvidenceStimulates chloride and fluid secretion through CFTR activation, increasing intestinal water content by approximately 15-25%.
Reduced Bloating Symptoms
Moderate EvidenceDecreases abdominal distension and bloating through improved gas and fluid movement, with symptom relief reported in 50-60% of patients.
Improved Quality of Life Scores
Moderate EvidenceEnhances overall well-being and daily functioning as measured by standardized questionnaires, with significant improvements in work productivity and social activities.
Research Dosing Protocols
Research Purposes Only: All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
| Research Protocol | Dose Range | Route |
|---|---|---|
| IBS-C research | 145–290 mcg | oral |
| Chronic constipation study | 72–145 mcg | oral |
| GC-C receptor investigation | 30–145 mcg | oral |
Frequency
Once daily
Timing
30 minutes before first meal of the day
Cycle Length
Continuous administration for research protocols
Research Notes
- 1Take on empty stomach for optimal absorption
- 2Swallow capsules whole - do not open or crush
- 3Research protocols typically last 12-26 weeks
- 4Maintain consistent timing for steady-state effects
Reconstitution Guide
Standard Reconstitution
Vial Size
0 mg
Bacteriostatic Water
0 mL
Concentration
NaN mcg
per 0.1 mL (10 units)
Step-by-Step Guide
Gather Materials
Linaclotide vial, bacteriostatic water, alcohol swabs, insulin syringes.
Equilibrate Temperature
Remove the vial from storage and allow it to reach room temperature (5-10 minutes).
Sanitize
Swab the rubber stopper of both the peptide vial and bacteriostatic water vial with alcohol.
Draw Water
Draw 0 mL of bacteriostatic water into a syringe.
Add Water to Vial
Insert the needle into the peptide vial and direct the water stream against the glass wall — not directly onto the powder.
Mix Gently
Swirl the vial gently until the powder is fully dissolved. Never shake. The solution should be clear and colorless.
Store Properly
Refrigerate at Not applicable. Not applicable.
Storage Temperature
Not applicable
Shelf Life
Not applicable
Important Notes
- •Linaclotide is available as oral capsules, not requiring reconstitution
Linaclotide Dosing Calculator
Calculate daily intake, cycle totals, and vials needed with pre-filled protocols →
Linaclotide Reconstitution Calculator
Calculate concentration, syringe units, and doses per vial with auto-filled values →
Safety & Side Effects
Reported Side Effects
- !Diarrhea (most common, occurring in 15-20% of users)
- !Abdominal pain and cramping
- !Flatulence and gas
- !Abdominal distension
- !Nausea
- !Headache
- !Viral gastroenteritis
- !Fatigue
- !Dehydration (with severe diarrhea)
Potential Interactions
- ⚡Antispasmodic medications may reduce effectiveness
- ⚡Loperamide and other antidiarrheal agents
- ⚡Medications requiring specific gastric pH for absorption
- ⚡Strong CYP3A4 inhibitors (theoretical interaction)
Important: Side effects and interactions listed here are compiled from published research and community reports. This is not a complete list. No formal drug interaction studies have been conducted for most research peptides. Always consult a qualified healthcare provider.
Research Studies
The following studies are referenced in this profile. PubMed IDs are provided where available for independent verification.
Efficacy and Safety of Linaclotide in Patients With Irritable Bowel Syndrome With Constipation
Phase III trial demonstrating significant improvements in bowel movement frequency and abdominal pain in 805 IBS-C patients over 12 weeks.
Linaclotide Improves Abdominal Pain and Bowel Habits in a Phase IIb Study of Patients with Irritable Bowel Syndrome with Constipation
Dose-ranging study showing optimal efficacy at 290 mcg daily with significant improvements in multiple endpoints.
Mechanisms of Linaclotide in Patients with Chronic Constipation
Mechanistic study demonstrating accelerated colonic transit and increased stool water content in chronic constipation patients.
Long-term Safety and Efficacy of Linaclotide in Patients with Irritable Bowel Syndrome with Constipation
52-week safety extension study confirming sustained efficacy and acceptable safety profile in IBS-C patients.
Note: This is not an exhaustive list of all published research. Studies are selected for relevance and quality. Click PubMed IDs to verify sources independently. Inclusion does not imply endorsement of the peptide for any clinical use.
Frequently Asked Questions
Linaclotide typically begins working within 24-48 hours of the first dose, with maximum benefits occurring after 1-2 weeks of consistent daily use. Some patients may experience bowel movement improvements within hours of taking their first dose.
Linaclotide should be taken on an empty stomach, at least 30 minutes before the first meal of the day. Taking it with food can reduce its effectiveness and increase the risk of side effects.
If you miss a dose, skip the missed dose and take the next dose at the regular time the following day. Do not take two doses on the same day to make up for a missed dose.
Yes, diarrhea is the most common side effect, occurring in 15-20% of users. Severe diarrhea can lead to dehydration and electrolyte imbalances. Contact a healthcare provider if diarrhea persists or becomes severe.
Clinical studies up to 52 weeks show linaclotide maintains its safety profile with continued use. However, long-term safety beyond one year requires ongoing monitoring and should be discussed with healthcare providers.
No significant interactions between linaclotide and probiotics have been reported. However, timing may be important - consider taking probiotics several hours after linaclotide to avoid potential interference.
No, linaclotide capsules should be swallowed whole and never opened, crushed, or chewed. Opening the capsules can affect the medication's effectiveness and increase side effect risks.
The 290 mcg dose is typically used for IBS with constipation, while 145 mcg is often prescribed for chronic idiopathic constipation. Higher doses provide greater symptom relief but may increase diarrhea risk.
Research & Educational Use Only
All content is for informational and research purposes only. This site does not provide medical advice, diagnosis, or treatment. Consult a qualified healthcare professional before using any peptide or supplement.
The information presented here is compiled from published research studies and is intended for informational purposes only. Individual results may vary. Always consult with a licensed healthcare provider.