Managing Diarrhea on GLP-1s Guide

Diarrhea is a common side effect of GLP-1 medications and/or Metformin. It often happens when you first start treatment or increase your dose.

This side effect is usually temporary. GLP-1 medications can change how your digestive system works while your body adjusts. In most cases, diarrhea gets better within 3 to 4 weeks.

Managing diarrhea is important, since it can lead to dehydration if it isn't treated. If you have diarrhea, the following steps may help.

First Step: Check for Other Causes

Before treating diarrhea as a medication side effect, make sure something else isn't going on.

Contact the Calibrate Clinical Team first if:

  • Your diarrhea started without a recent dose increase
  • You've had several days without a bowel movement, followed by diarrhea (this can be overflow diarrhea caused by constipation, and it needs different treatment)
  • You've taken antibiotics recently
  • You have a fever, stomach pain, or blood in your stool

Second Step: Diet and Lifestyle Changes

Drink plenty of fluids

Diarrhea causes your body to lose water and electrolytes quickly. It's important to replace both.

Adding a small pinch of salt to your water can help. Eating potassium-rich foods such as avocado, leafy greens, zucchini, and sweet potato can also help. Bone broth also helps (Kettle & Fire if you don't make your own). Electrolyte powders work too (LMNT unflavored, Redmond Re-Lyte).

Avoid foods that make It worse

Some foods and drinks can speed up your digestive system and make diarrhea worse, including:

  • Caffeine
  • Dairy
  • Sugar
  • Fried foods
  • Spicy foods
  • Hot drinks

Watch for your own personal triggers

GLP-1 medications slow down digestion, so foods your body normally tolerates in small amounts — like dairy, if you're lactose intolerant — can sit in your system longer and cause worse symptoms than usual. If you notice diarrhea after eating a specific food, even one not on the list above, try cutting it out for a few days to see if things improve. A simple food diary (noting what you eat and when symptoms show up) can help you and the Clinical Team spot patterns.

Increase soluble fiber

Soluble fiber absorbs water and adds bulk to your stool, which can slow things down.

Good sources include:

  • Apples
  • Beans
  • Citrus fruits

Try calming breathing before meals

For 1 minute before eating and 4 minutes after, sit quietly and take slow, deep breaths into your belly. This can help calm your digestive system. Repeat as often as needed.

Third Step: Over-the-Counter Treatments

These treatments are meant for short-term relief.

Bismuth Subsalicylate

Available as Pepto-Bismol or Kaopectate. Do not use it if you take aspirin or blood thinners, or if you're allergic to salicylates. May temporarily turn your tongue or stools black/dark — this is harmless and expected, not a sign of bleeding.

Loperamide

Available as Imodium. Do not use it for more than 2 weeks at a time. Stop using it and contact the Clinical Team if you develop worsening stomach pain, bloating, or swelling. GLP-1 medications already slow down your digestive system, so this combination needs extra caution.

Fiber Supplement

Psyllium supplements, such as Metamucil, are a concentrated source of soluble fiber. Follow the label instructions for "Relief of Irregularity."

Fourth Step: Medication Adjustment

If diarrhea continues, your GLP-1 dose may need to be adjusted for a short time. Please contact your Calibrate Clinical Team to discuss your symptoms.

When to Contact the Calibrate Clinical Team

Please contact us through the Support Center in the app if:

  • Your symptoms are persisting for more than 7 days despite recommendations
  • Your diarrhea is getting significantly worse
  • You are worried about dehydration
  • You are experiencing diarrhea and have underlying kidney disease
  • You have questions about diarrhea or its treatment

When to Seek Urgent Medical Care

Seek medical care right away if you have any of the following:

  • Signs of dehydration (dizziness, dark urine, peeing much less than usual)
  • Severe abdominal pain, bloating, or swelling
  • Blood in your stool or rectal bleeding
  • Fever, a fast heart rate, or feeling very weak
  • Symptoms that feel urgent or severe

These symptoms may be signs of a more serious medical problem and should be evaluated as soon as possible.