Managing constipation on GLP-1 medications
Constipation is one of the most common but least-discussed side effects of GLP-1 medications. It is not just about food — slowed gastrointestinal transit plus reduced total food intake produces a predictable pattern.
Why it happens
GLP-1 receptor agonists slow not just gastric emptying but transit time throughout the gut. With smaller meals and reduced fiber intake, stools become drier, smaller, and slower-moving. The combination — slower motility plus reduced bulk — is what makes constipation common.
Hydration
Aim for steady water intake throughout the day rather than just at meals. With smaller meals you may not feel as thirsty, so you have to remind yourself. Many patients find that bumping water to 2-3 liters per day improves things within a week.
Fiber strategy
Soluble fiber — found in oats, chia seeds, ground flax, kiwi, beans, apples — tends to be gentler than insoluble fiber for people on GLP-1 medications. Adding too much insoluble fiber (raw bran, large salads) can sometimes worsen the bloating sensation. Psyllium husk is a well-tolerated supplement option.
Movement
Even a 15-20 minute walk improves bowel motility for many patients. Most randomized trials of laxatives use 'increase physical activity' as a comparator, and it typically beats no intervention.
Adjuncts to discuss with your prescriber
Magnesium (citrate or hydroxide form) is a commonly used osmotic that can help. Polyethylene glycol (Miralax) is well-tolerated and evidence-based. Stool softeners like docusate are often used. Stimulant laxatives (senna, bisacodyl) should be short-term only and discussed with your clinician. Do not stack multiple agents without guidance.
When to seek medical care
Several days without a bowel movement, severe abdominal pain, vomiting alongside constipation, blood in stool, or symptoms that change in character (new pain, new pattern) all warrant calling your clinician. Bowel obstruction is rare but serious.
Last reviewed: 2026-05-24