How to Manage Constipation on GLP-1 Medications

Constipation is one of the most common side effects of GLP-1 medications — second only to nausea, especially in the first weeks and after a dose increase. The good news: a few simple eating and hydration habits make a big difference.

Why GLP-1 medications cause constipation

GLP-1 medications slow how quickly food moves through your stomach and gut. That's part of how they curb appetite — but the same slowing of intestinal transit is a common cause of constipation. A smaller appetite often means you're also eating less fibre and drinking less, which compounds the problem.

Get enough fibre — the right way

• Aim for roughly 25 g of fibre a day (women) and up to ~38 g (men).
• Mix soluble fibre (oats, beans, lentils, apples, psyllium) with insoluble fibre (whole grains, vegetables, skins).
• Increase fibre gradually and with plenty of fluid — adding fibre without water can actually make constipation worse.
• Because your appetite is small, lead with nutrient- and fibre-dense foods so every bite counts. See our high-protein foods guide and the recipes for fibre-rich, high-protein options.

Drink more than you think

GLP-1 medications blunt thirst as well as hunger, so mild dehydration sneaks up — and adequate fluid is central to managing these GI side effects. Sip water steadily through the day rather than relying on feeling thirsty.

Keep moving

Gentle, regular movement — even a daily walk — helps keep your digestion moving. It's a simple, no-downside habit that supports everything above.

Supplements: check first

Some people use a psyllium fibre supplement or magnesium to stay regular. These can help, but they should fit your overall plan — check with your doctor or pharmacist first, especially alongside other medications. We don't provide dosing advice.

When to see a doctor

Contact your healthcare provider if constipation is severe, lasts more than a few days, or comes with significant pain, bloating, or vomiting. They can adjust your dose or rule out other causes.

This is general nutrition information, not medical advice. For persistent or severe symptoms, or before starting any supplement, talk to your doctor or dietitian.