GLP-1 Constipation: Prevention & Relief

The side effect that catches people off guard

While nausea gets most of the attention, constipation is equally common — affecting approximately 20-30% of people during GLP-1 treatment. The mechanism: GLP-1 slows movement of food through the entire GI tract, including the colon. Slower transit means more water is absorbed from stool, making it harder to pass.

Prevention: the most effective strategy

The three pillars are water, fiber, and movement.

• Water — aim for 80-100+ ounces daily. Slowed colon transit means more water extracted from stool. Warm water with lemon in the morning can stimulate bowel motility.
• Fiber — aim for 25-30g daily from vegetables, fruits, whole grains, legumes, and seeds. Increase gradually to avoid bloating.
• Movement — even light walking stimulates colon motility. A 10-15 minute walk after meals is particularly effective.
• Magnesium — magnesium citrate or oxide taken at bedtime can help maintain regularity. Discuss dosing with your provider.

Over-the-counter options if prevention is not enough

Osmotic laxatives like polyethylene glycol draw water into the colon and are gentle with low dependence risk. Fiber supplements like psyllium husk add bulk — take with plenty of water. Avoid stimulant laxatives containing senna or bisacodyl for routine use — they can cause dependence. Discuss any supplement or medication with your provider before starting.

When to contact your provider

Contact your provider for: constipation lasting more than one week despite prevention and OTC measures, severe abdominal pain or bloating, or inability to pass gas along with constipation (could indicate bowel obstruction — seek urgent care).