Acid Reflux and Heartburn on GLP-1: Why It Happens and How to Manage It
GLP-1 reflux comes from food sitting in your stomach longer. Eat smaller meals, finish eating 3+ hours before bed, sleep slightly elevated, avoid trigger foods (alcohol, citrus, mint, fatty/spicy), and use famotidine (Pepcid) or PPIs short-term if needed.
Acid reflux is an under-discussed but increasingly common GLP-1 side effect. Roughly 15% of patients report new or worsened heartburn, and the mechanism is direct: food that should have left your stomach in 90 minutes is still there at hour 3.
Why GLP-1 causes reflux
Slowed gastric emptying means more food in the stomach at any given time, which:
- Increases pressure on the lower esophageal sphincter (LES)
- Provides more substrate for acid production
- Makes lying down within a few hours of a meal much more reflux-prone
- Worsens existing GERD that was previously controlled
The behavioral fix
Most cases respond to behavior, not medication.
Eat smaller meals. 4–6 oz portions, more often. A large meal on a slow stomach is essentially asking for reflux.
Finish eating 3 hours before bed. This is the single most important rule. The meal you eat at 9 pm is still in your stomach at midnight when you lie down — and that meal becomes reflux. Move your last meal to 6 pm and most reflux disappears.
Elevate the head of your bed. A 6–8 inch wedge under the mattress (not just extra pillows, which bend you at the waist and worsen reflux) keeps gravity working in your favor.
Identify your triggers. The big ones:
- Alcohol (relaxes the LES)
- Citrus and tomato (acidic, irritating)
- Mint (relaxes the LES — surprising)
- Chocolate (caffeine + relaxant compounds)
- Fatty foods (slow gastric emptying further)
- Spicy foods (direct mucosal irritation)
- Carbonated drinks (gas pressure)
Walk after eating. A 10-minute walk after a meal accelerates gastric emptying modestly. Better than sitting on the couch.
Medications that help
If behavior changes are not enough:
Famotidine (Pepcid). 20 mg before bed (or before known trigger meals) is well-tolerated and works for mild-moderate reflux. OTC.
Calcium carbonate (Tums). Acute relief, not a daily fix. Useful in the moment.
Alginate-based products (Gaviscon). Form a foam barrier on top of stomach contents. Surprisingly effective for nighttime reflux.
Proton pump inhibitors (omeprazole, esomeprazole). Most effective. Aim for short-term use (4–8 weeks) and then taper. Long-term PPI use has its own concerns (B12 absorption, magnesium, infection risk).
When reflux on GLP-1 is a red flag
- Difficulty swallowing
- Food getting stuck
- Vomiting blood or coffee-ground material
- Black, tarry stools
- Significant unintended weight loss beyond what the medication explains
- Chest pain that could be cardiac (or might just be reflux — when in doubt, get checked)
Bottom line
GLP-1 reflux is mechanical: more food in the stomach for longer. Eat smaller meals, stop eating 3 hours before bed, elevate the bed, and skip the trigger foods. Famotidine before bed handles the rest for most patients. Persistent severe reflux warrants endoscopy, especially in patients with risk factors for Barrett's esophagus.