Constipation on GLP-1 Medications: Causes and Solutions

Why GLP-1s Cause Constipation

GLP-1 medications slow gastric emptying and intestinal transit — food moves through your system more slowly. Combined with eating less food (less fiber, less bulk) and potential dehydration, constipation is one of the most common side effects.

What Works

Fiber (but the right kind)

• Psyllium husk (Metamucil): 1 tablespoon in water, 1-2x daily
• Ground flaxseed: 2 tablespoons daily
• Avoid insoluble fiber supplements if already bloated — they can worsen it

Hydration

• Minimum 64oz water daily, ideally 80-100oz
• Warm water in the morning stimulates motility
• Avoid excess caffeine (dehydrating)

Magnesium

• Magnesium citrate: 200-400mg at bedtime (gentle osmotic laxative)
• Magnesium oxide: stronger, use for acute relief
• Safe for daily long-term use

Movement

• Walking 20+ minutes daily significantly improves gut motility
• Even light activity after meals helps

Timing

• Constipation is usually worst during the first 2-3 weeks at each new dose
• It typically improves as your body adjusts

When to See Your Provider

• No bowel movement for 4+ days
• Severe abdominal pain or bloating
• Blood in stool
• Symptoms worsening despite interventions

What NOT to Do

• Don't use stimulant laxatives (Dulcolax, Senna) daily — creates dependency
• Don't skip meals entirely — some fiber/bulk is needed
• Don't reduce water intake