Does Wegovy Make You Constipated?

You've just started Wegovy and your bowel habits have changed

This is a question our prescribers hear most weeks: a patient has been on treatment for two or three weeks and notices they are going far less frequently than usual. Sometimes stools are harder; sometimes a day or two simply passes with nothing. It can feel alarming when you are already paying close attention to how your body is responding to something new.

The mechanism is straightforward. Semaglutide activates GLP-1 receptors, which signal the gut to slow down. That slowing is deliberate and is part of what keeps you fuller for longer between meals. The same signal that tells your stomach to hold onto food longer also affects intestinal transit more broadly. The NHS medicines page for semaglutide lists constipation among the common side effects, alongside nausea, vomiting and indigestion.

For most people, constipation is most noticeable in the early weeks of each dose level, particularly after a dose increase. As your body adjusts, gut motility often partially recovers and things settle. Drinking more water, adding soluble fibre (oats, lentils, flaxseed), keeping physically active and not ignoring the urge to go all help. Reducing ultra-processed foods and increasing vegetables is the kind of dietary shift that supports treatment anyway, and it also keeps things moving. If things remain very uncomfortable, your prescriber may discuss options; do not start any laxative routinely without checking first, since they interact differently with different people on GLP-1 treatment.

For more practical guidance on managing this, the constipated on Wegovy page goes through specific steps in detail.

When constipation on semaglutide becomes a warning sign rather than a nuisance

Most of the time, constipation on Wegovy is uncomfortable but not dangerous. There are situations, though, where bowel symptoms need proper clinical assessment rather than a home remedy.

Stomach pain that is severe and does not pass, especially if it radiates toward the back, is not something to sit with. Acute pancreatitis is a known, if infrequent, serious side effect of GLP-1 medicines. In January 2026 the MHRA issued a Drug Safety Update specifically highlighting acute pancreatitis for this medicine class: the message was clear that persistent, severe abdominal pain, with or without vomiting, should prompt urgent medical help. Constipation itself does not cause that pattern of pain, so if your symptoms don't fit the usual picture of a sluggish bowel, seek help promptly.

Other signs that warrant a call to your GP or 111, rather than waiting it out: blood in your stool, severe bloating alongside an inability to pass wind for more than a day or two, or any dramatic change in your pattern that feels distinctly different from the early-weeks adjustment. If you become significantly dehydrated through severe nausea or vomiting alongside constipation, that also needs clinical attention, since dehydration worsens constipation and can affect kidney function. You can read more about the full side-effect profile of Wegovy to understand the broader picture.

You can report a suspected side effect directly to the MHRA through the Yellow Card scheme. You do not need a GP to do this; patients can submit reports themselves, and it helps the MHRA monitor real-world safety signals for newer medicines.

Does constipation mean Wegovy is not working, or should you reduce your dose?

Not at all. Constipation and weight loss are separate processes, and tolerating some gut adjustment early in treatment does not mean anything has gone wrong. If you are wondering why Wegovy makes you constipated and what you can do about it, the side-effect profile of semaglutide, documented in the STEP 1 trial published in the New England Journal of Medicine, reflects what happened across thousands of participants on a structured titration schedule: GI effects were common at the start and tended to diminish over time.

Whether to push through a difficult patch, slow down the titration, or adjust something else is a clinical question. It depends on how significant your symptoms are, how long they have lasted, and what else is going on. A prescriber who knows your history can weigh that up properly. Reducing your dose without guidance, or stopping treatment abruptly, is not the right answer for everyone, and doing so may mean losing the appetite effect before your body has had the chance to adapt.

If you are thinking about whether Wegovy is the right treatment for you, or you have questions about how side effects are managed from the start, a free consultation with our clinical team covers that conversation before anything is prescribed. You can also read the broader Wegovy treatment overview to understand how the medicine works and what to expect across the full course. People already on treatment who have specific worries can reach us through our support line, which is available seven days a week.

For those comparing treatment options or thinking about cost, the Wegovy price comparison page sets out what private treatment typically involves, while the treatment overview covers both Wegovy and Mounjaro so you can see what suits your situation.