Why Semaglutide Causes Diarrhea: Understanding GLP-1 Effects on Gut Motility & Digestion

Diarrhea is a common gastrointestinal side effect of semaglutide, especially as the medication alters how quickly food moves through the digestive system.

Symptoms are most likely to appear during dose increases or near the target dose and often improve as the body adjusts over time.

Dehydration is a primary concern when diarrhea occurs, making fluid and electrolyte replacement an important part of symptom management.

Eating smaller, blander meals and avoiding greasy, spicy, or very sweet foods can help reduce gastrointestinal discomfort while on semaglutide.

Severe or persistent abdominal pain, ongoing diarrhea, signs of dehydration, or fever warrant contacting a healthcare provider for further evaluation.

Semaglutide is massively popular. But like all medications, it comes with side effects. Whether you’ve been taking it for diabetes or weight management, if you’ve noticed some unwelcome changes to your bowel movements, know that you’re not alone.

Diarrhea is among the most common Ozempic or Wegovy side effects. That’s down to how GLP-1s affect your gut and digestive system. Let’s break down the mechanisms at play and explain how you can take charge of managing semaglutide side effects.

What Are GLP-1s?

Ozempic and Wegovy contain the active ingredient semaglutide; a GLP-1, or “glucagon-like peptide 1” receptor agonist. Put simply, this compound binds to key sites in your brain, pancreas, and gastrointestinal (GI) tract, instigating several potent reactions:

• Enhances insulin secretion
• Slows gastric emptying
• Increases β-cell proliferation
• Reduces glucagon release
• Mitigates hunger signaling

All of which combine to regulate how often you feel like eating, how much food you consume, how full it makes you feel, and how long you hold onto that feeling of satiety.

How Semaglutide Affects Your Gut

When it comes to medication, side effects generally correlate with potency. In the case of GLP-1s, their relatively mild side effect profile compared to their efficacy is one of the biggest selling points.

That said, Ozempic, Wegovy, and Rybelsus (the three brand names for semaglutide) primarily lead to “mild-to-moderate and transient gastrointestinal disturbances” like nausea, vomiting, and diarrhea. For the latter, some data have shown diarrhea to affect up to 10% of users.

How? By binding to regional receptors in the gastrointestinal tract, GLP-1s alter gut motility in different areas of your intestines, affecting the physical contractions which push food (and waste) through your body.

The Physiology of Diarrhea

According to the Mayo Clinic, diarrhea is characterized by “loose, watery, and possibly more-frequent passage of stool.” However, physical expulsions are not the sole symptom; diarrhea sufferers may also experience blood or mucus in stool, stomach cramps, dehydration, or even fever.

Semaglutide Diarrhea Causes, Explained

You can think of disruptions to your GI system like an intersection that desperately needs a traffic cop but doesn’t have one; instead of a smooth, consistent flow of traffic, cars (food waste) may start and stop sporadically, creating backup, congestion, and bursts of rapid movement.

Semaglutide Dose Titration and Side Effect Timeline

Per the FDA, most patients effectively mitigate gastrointestinal issues by following semaglutide’s titration schedule—a planned and gradual increase in dosage over a period of months. Semaglutide’s starting dose begins at a modest .25mg, usually administered as a weekly injection, and gradually escalates to a target dose of 2.4mg after roughly 16 weeks.

If you’re using semaglutide, you’re more likely to experience gastrointestinal symptoms—including but not limited to diarrhea—during or shortly after arriving at the target dose.

It’s also worth noting that, while relatively common, diarrhea is not a persistent side effect of semaglutide. For most people, it lasts a few days to a week and then at least partially subsides as your body adjusts to the medication.

Managing Diarrhea on Semaglutide: Evidence-Based Strategies

If you’re experiencing diarrhea or other GI side effects from GLP-1s, know that there are ways to make the stomach storm easier to weather until it passes. Tidying up your diet and taking certain over-the-counter supplements are strategies worth looking into.

Dietary Adjustments

It may serve the same general purpose, but your stomach isn’t as crude as a mechanical food processor. Your GI tract is a robust and intricate system with its own internal biome. The quality, quantity, and frequency of eating influence how cleanly this organic machine can fulfill its duty.

Luckily, you can make simple and intuitive changes to your diet that may mitigate the incidence of diarrhea. Studies tell us that anti-inflammatory foods, an emphasis on whole grains, drinking more water, and replenishing lost electrolytes are key.

Stanford Health recommends avoiding greasy, spicy, highly seasoned, or overly sweet foods, and to not gorge on large, infrequent meals.

Over-the-Counter Options

You may also want to head to the supplement rack to get a handle on diarrhea symptoms. There are several options, holistic and pharmaceutical, if you’re suffering from GI distress on semaglutide.

• Probiotics have been shown to be potentially effective in reducing diarrhea duration and frequency, though these data were gathered on children and may not be applicable to adults on semaglutide.
• Zinc has some clinical backing in improving symptoms of diarrhea.

Soluble fiber is recommended by the International Foundation for Gastrointestinal Disorders as a bulking agent to reduce watery stool. The foundation also highlights Imodium as the safest and best “emergency treatment” OTC drug for diarrhea, though it may come with its own gastrointestinal sides.

When To Contact Your Doctor

For most people, diarrhea amounts to little more than a nuisance—an unprompted and potentially uncomfortable run (or three) to the restroom. In some cases, things are more severe. Whether you’re on GLP-1s or not, persistent diarrhea merits a doctor’s visit.

Recognizing Warning Signs

Science regards diarrhea as “one of the most common global health concerns” due to its propensity to create malnutrition, exhaustion, and nutritional deficiencies. A few days of unpleasant bouts on the toilet while adjusting to GLP-1s are tolerable, but you should be acutely mindful of more serious side effects:

• Intense stomach pains, even while not on the toilet
• Dehydration, presented as altered urination, light-headedness, or fatigue
• Fever

Remember—while unpleasant, diarrhea is usually manageable at home and does not impact 100% of people taking Ozempic, Wegovy, or Rybelsus. Still, if you’re suffering and displaying other symptoms, it’s best to play things safe and seek out medical treatment.

If side effects are affecting your experience or raising questions about next steps, a short assessment can help provide clarity. At SkinnyRx, this assessment is reviewed by a licensed medical provider to help determine appropriate weight loss options based on your health history, symptoms, and goals.