Diarrhea on GLP-1 medicines

In short

Loose stools are common in the early weeks of a GLP-1 and after dose increases. Most cases are mild, but ongoing diarrhea can drain fluids and needs attention.

Why it happens

GLP-1 medicines change how the gut moves food and fluid. That can speed things up lower in the gut even while the stomach empties more slowly.

Diet changes also play a part. Sugar alcohols in protein bars, large amounts of fat and sudden jumps in fiber can all loosen stools.

When it starts and fades

Diarrhea is most common in the first weeks of treatment and after dose steps. In the trials, stomach side effects were mostly mild to moderate and most frequent during dose escalation.

For many people it settles as the body adjusts. If it persists beyond a few days, or comes with signs of dehydration, contact your prescriber.

What helps

• Drink extra fluids, and consider an oral rehydration drink if stools are frequent.
• Limit greasy foods, very spicy dishes and large servings of dairy if they bother you.
• Check labels for sugar alcohols like sorbitol and maltitol in bars and shakes.
• Eat smaller, simpler meals until things settle.
• Add fiber slowly rather than all at once.
• Keep notes on foods and timing to spot your personal triggers.