Yes, semaglutide can cause diarrhea, and it's one of the most common side effects of weight loss medications like Ozempic and Wegovy. In clinical trials, 74% of people experienced gastrointestinal side effects including diarrhea when taking semaglutide for weight loss . The good news: for most people, symptoms improve within a few days as the body adjusts to the medication. Understanding why this happens and what you can do about it can make the experience much more manageable.

Why Does Semaglutide Cause Diarrhea?

Semaglutide works by mimicking a hormone called glucagon-like peptide-1 (GLP-1), which plays a role in digestion, appetite, and insulin release. But here's where things get complicated: GLP-1 receptors are found throughout your gastrointestinal tract, not just in your brain. When semaglutide activates these receptors, it changes how your digestive system operates in several ways .

The medication affects your gut in three main ways:

• Slowed Gut Movement: Semaglutide slows gastric emptying and motility throughout the GI tract, which contributes to feelings of fullness but can also disrupt normal digestion. Food ends up sitting longer in the stomach and intestines, and this delayed movement has been associated with an increased risk of small intestinal bacterial overgrowth (SIBO), which can cause diarrhea.
• Altered Hormone Signaling: Activating GLP-1 receptors throughout the gastrointestinal tract can change how the intestines secrete fluids and handle nutrients, which may contribute to diarrhea.
• Body Adjustment Period: A key reason diarrhea appears when starting semaglutide or increasing your dose is that your body isn't yet accustomed to the medication. This is why healthcare providers typically recommend gradually increasing the dosing over time.

For most people, semaglutide diarrhea is temporary. It tends to appear when first starting the medication or increasing the dose, and improves within a few days per episode as the body adjusts. How long it lasts can vary depending on the dose, how quickly it's increased, and individual sensitivity .

How Long Does Semaglutide Diarrhea Last?

The timeline varies from person to person. Some people experience symptoms for just a few days, while others may have them for longer, especially during dose adjustments. The pattern healthcare providers tend to see is that diarrhea often appears early in treatment, is usually mild to moderate, and tends to get better as the body adjusts .

If your symptoms are mild to moderate, simple strategies are often enough to help you get through it. However, if your diarrhea lasts more than a week, occurs frequently, or is severe, it's important to reach out to your healthcare provider. They can determine whether to pause, lower, or slow dose escalation, or try additional treatments.

Ways to Manage Semaglutide Diarrhea

• Adjust Your Eating Habits: Larger meals and high-fat, greasy, or very rich foods are more likely to trigger diarrhea while taking semaglutide. Stick to smaller, more frequent meals and simpler foods such as lean protein, rice, toast, and bananas while symptoms settle.
• Stay Hydrated: Diarrhea can lead to fluid loss quickly. Drinking enough water is important for preventing dehydration. Drinking electrolyte-rich fluids containing sodium and potassium can help replace what the body loses and support proper hydration.
• Avoid Trigger Foods and Drinks: Certain foods and drinks can irritate the digestive system and make diarrhea worse, including alcohol, caffeine, spicy foods, products with artificial sweeteners like candy and gum, dairy products (especially if you are lactose intolerant), and soft drinks. Cutting back, at least temporarily, can help reduce symptoms while the gut is more sensitive.
• Slow Your Dose Increases: Diarrhea is more likely during dose escalation. If symptoms feel intense, it's worth reaching out to your healthcare provider. They may recommend staying at the current dose longer before increasing, or temporarily lowering it, giving the body more time to adjust.
• Consider Over-the-Counter Options: In some cases, over-the-counter anti-diarrheal medications such as loperamide (Imodium) can help manage symptoms by slowing gut movement and giving the body more time to absorb fluids. Loperamide is generally safe for short-term use, but checking with a healthcare provider first is recommended, especially when using it regularly.

When Should You Contact Your Healthcare Provider?

While mild to moderate diarrhea is a common side effect, more intense or long-lasting symptoms can lead to dehydration or signal that the dose needs adjusting. You should contact a healthcare provider if you experience diarrhea lasting more than a week, frequent or severe episodes, signs of dehydration such as dizziness, dry mouth, or dark urine, trouble keeping fluids down, blood in your stool or black stools, or severe abdominal pain .

"Yes, diarrhea is a known side effect of semaglutide, especially when first starting or increasing the dose. Semaglutide diarrhea usually improves within a few days as the body adjusts, though timing varies," explained Dr. Raagini Yedidi.

Dr. Raagini Yedidi, Internal Medicine Resident and Medical Reviewer at Ro

The bottom line: semaglutide diarrhea can be frustrating, but it's usually temporary and manageable. It often appears early in treatment or during dose increases, and for many people, it improves as the body adjusts. Simple adjustments to eating habits, hydration, and dose escalation pace can help reduce symptoms significantly. Most cases are mild, but persistent or severe diarrhea should be checked by a healthcare provider to rule out other issues and ensure you're staying properly hydrated .