Wegovy causes constipation because its active ingredient activates receptors throughout your digestive tract that slow down muscle contractions in the intestines. This is the same mechanism that helps you feel full longer and eat less, but the tradeoff is that food and waste move through your system much more slowly than usual. In clinical trials, constipation was one of the most common side effects, with episodes lasting a median of 47 days in people taking semaglutide compared to 35 days for those on placebo.
How Wegovy Slows Your Gut
Wegovy works by mimicking a natural hormone called GLP-1, which your body produces after eating. GLP-1 receptors aren’t just in the pancreas. They’re scattered throughout the central nervous system, the vagus nerve, and critically, the enteric nervous system, which is the network of nerves embedded in the walls of your intestines that controls digestion independently of your brain.
When semaglutide activates these receptors in the gut wall, it reduces the strength of the circular muscle contractions that push food and waste forward through the intestines. Research on intestinal tissue has shown that GLP-1 specifically dampens the nerve signals (called cholinergic contractions) responsible for this forward motion. The drug triggers the release of nitric oxide in gut neurons, which acts as a brake on those propulsive contractions. In the colon, 79% of the neurons that carry GLP-1 receptors also produce this braking compound, which helps explain why constipation is such a predictable side effect.
The medication also increases the stomach’s volume and slows gastric emptying, meaning food sits in your stomach longer before moving into the small intestine. This cascade effect means everything downstream moves more slowly too. By the time waste reaches the colon, more water has been absorbed from it, making stools harder and more difficult to pass.
Reduced Eating and Drinking Make It Worse
The biological slowdown is only part of the story. Wegovy also suppresses your appetite and, less obviously, dials back your sense of thirst. Both of these behavioral changes compound the constipation problem.
When you eat significantly less food, you take in less fiber, the key ingredient that adds bulk and moisture to stool. Many people on Wegovy also shift toward higher-protein, lower-volume meals, which can further reduce fiber intake. At the same time, drinking less water means less fluid is available in the intestines to keep things soft and moving. The combination of slower transit, less fiber, and less hydration creates ideal conditions for constipation.
When Constipation Typically Starts and Peaks
Constipation tends to appear during or shortly after Wegovy’s dose-escalation period, when your dose is gradually increased every four weeks. In clinical trials pooling data from the STEP studies, the prevalence of constipation plateaued around week 10. Most gastrointestinal side effects were concentrated in the first 20 weeks, with the rate of new cases leveling off after that point.
The good news is that for most people, the severity decreases over time. In participants who stayed on semaglutide 2.4 mg, the prevalence of constipation declined after the dose-escalation period ended. Your body does adapt, though “adapt” doesn’t always mean the constipation disappears entirely. Some people experience it as a persistent, low-grade issue for as long as they take the medication.
Managing Constipation on Wegovy
Three lifestyle adjustments make the biggest difference: fiber, water, and movement.
- Fiber: Aim for 25 to 30 grams per day, increasing gradually to avoid gas and bloating. Since you’re eating less overall, you may need to be more deliberate about choosing high-fiber foods like vegetables, beans, berries, and whole grains. Fiber acts as a prebiotic too, feeding beneficial gut bacteria that support healthy digestion.
- Hydration: Target 8 to 10 cups of water daily. Because the medication blunts your thirst signals, you may need to set reminders or keep a water bottle nearby rather than relying on feeling thirsty.
- Physical activity: Regular movement stimulates the muscles in your intestinal walls. Even 20 to 30 minutes of brisk walking daily can make a noticeable difference. Yoga poses that compress and massage the abdomen are also helpful.
Establishing a consistent bathroom routine helps as well. Sitting down at the same time each day, ideally after a meal when your body’s natural digestive reflexes are strongest, gives your system a regular cue.
Why Laxatives Work Better Than Stool Softeners
If lifestyle changes aren’t enough, the type of over-the-counter product you reach for matters. Stool softeners work by adding moisture to stool, but they still rely on your intestinal contractions to push that softened stool through. Since Wegovy is actively slowing those contractions, softeners alone often fall short.
A stimulant or osmotic laxative is generally a better choice because it either triggers the contractions directly or draws water into the intestines to get things moving. Over-the-counter options in these categories are widely available. If you find yourself needing a laxative regularly, it’s worth discussing with your prescriber to make sure nothing else is going on.
When Constipation Signals Something More Serious
In rare cases, the intestinal slowdown caused by GLP-1 medications can progress beyond ordinary constipation. Case reports have documented pseudo-obstruction, a condition where the bowel stops moving effectively and mimics a physical blockage even though no blockage exists. Symptoms include significant abdominal pain, bloating, distension, and an inability to pass gas or stool.
A small number of case reports have also described actual bowel obstruction in people taking semaglutide or similar medications. In one case, a 29-year-old man developed a gastric outlet obstruction that resolved after three days of hospital care. Other reports have involved intussusception, where one section of intestine telescopes into another. These complications are rare, but they underscore why severe or worsening abdominal symptoms on Wegovy shouldn’t be written off as normal side effects.