GLP-1 medications work directly on the digestive system, slowing gastric emptying and altering gut motility. Understanding these effects helps you manage your treatment more effectively and recognize what's normal versus concerning.
How GLP-1s Affect Digestion
GLP-1 receptors are abundant throughout the gastrointestinal tract. When activated, these medications slow down how quickly food leaves your stomach (delayed gastric emptying), which contributes to feeling full longer but can also cause digestive changes.
- Delayed gastric emptying: Food stays in stomach 30-50% longer
- Reduced appetite: Brain signaling decreases hunger
- Slower intestinal transit: Food moves more slowly through gut
- Altered gut hormones: Changes in digestive enzyme secretion
- Microbiome shifts: Some studies show gut bacteria changes
Common Digestive Side Effects
Nausea (Most Common)
Affects 20-50% of users initially. Usually improves within 4-8 weeks as your body adapts.
Constipation
Slowed gut motility can reduce bowel frequency. Fiber and hydration help significantly.
Diarrhea
Less common but can occur, especially when eating high-fat foods.
Bloating and Gas
Food fermenting longer in the gut can increase gas production.
Acid Reflux
Slower stomach emptying can worsen GERD symptoms in some people.
Dietary Strategies for Better Digestion
- Eat smaller portions: Your stomach capacity effectively feels smaller
- Chew thoroughly: Aids digestion and signals fullness
- Avoid fatty/greasy foods: These digest slowest and cause most issues
- Stay upright after eating: Helps prevent reflux
- Space meals out: Allow 4-6 hours between substantial meals
- Prioritize protein first: Eat protein before carbs and fats
- Stay hydrated: Drink water between meals, not during
When to Seek Medical Attention
Contact your doctor if you experience severe abdominal pain, persistent vomiting (unable to keep fluids down), signs of dehydration, blood in stool, or symptoms of pancreatitis. Some digestive effects require dose adjustment or medication change.