How long does constipation last on Ozempic?

For most people, constipation is worst in the first 4-8 weeks of starting Ozempic or after each dose increase. As your body adapts to the medication, GI symptoms typically improve significantly. If severe constipation persists beyond 8 weeks, discuss it with your prescribing doctor as a dose adjustment or additional treatment may be needed.

Can I take a laxative while on Ozempic?

Yes, in most cases you can use gentle laxatives alongside Ozempic, but always check with your doctor first. Osmotic laxatives like polyethylene glycol (Movicol, available in SA pharmacies) or lactulose are generally considered safe. Stimulant laxatives should be used sparingly and only short-term. The better long-term approach is dietary fibre, adequate hydration, and gentle movement.

Is constipation more common than diarrhoea on Ozempic?

In clinical trials, nausea was the most common GI side effect (20-44% of users), followed by diarrhoea (about 8%) and constipation (about 5%). However, real-world reports suggest constipation may affect more people than clinical trials suggest, possibly because participants were carefully selected and monitored. Both constipation and diarrhoea can occur, sometimes alternating, especially during dose escalation phases.

Ozempic and Constipation: Managing GI Side Effects on Semaglutide (SA Guide 2026)

Q: Why does Ozempic cause constipation?

Ozempic (semaglutide) activates GLP-1 receptors throughout your gut, which slows gastric emptying (the rate food moves from your stomach to your intestines). This is intentional -- it helps you feel full longer and reduces appetite. But the same mechanism means food and waste move more slowly through your entire digestive tract, often resulting in constipation, bloating, and infrequent bowel movements.

By Weight Loss Diets SA | Updated June 2026 | 8 min read

You've started Ozempic (semaglutide), the injections are going well, and the appetite suppression is working exactly as promised. But your gut has other ideas. Constipation, bloating, and that uncomfortable feeling of things just not moving are among the most common complaints from South Africans using GLP-1 weight loss medications.

The good news: this is almost always temporary, manageable, and definitely not a reason to stop a medication that may be transforming your health. Here's exactly what's happening and what you can do about it.

Key takeaway: Constipation affects an estimated 5-24% of Ozempic users depending on the study. It's most common during dose increases and typically improves within 4-8 weeks as your body adapts. Dietary and lifestyle measures resolve it for most people without needing to stop the medication.

Why Does Ozempic Cause Constipation?

Semaglutide works by activating GLP-1 (glucagon-like peptide-1) receptors throughout your body. These receptors are found not just in your pancreas and brain, but densely throughout your entire gastrointestinal tract.

When semaglutide activates gut GLP-1 receptors, it slows gastric emptying — the rate at which food moves from your stomach into your small intestine. This is by design: slower gastric emptying means you feel fuller for longer, which is a key mechanism behind Ozempic's weight loss effects.

But the slowdown doesn't stop there. The entire gut motility — how quickly contents move through your intestines and colon — also decreases. The result: food and waste sit in your colon longer, more water gets absorbed, and stools become harder and less frequent. Hello, constipation.

When Is It Worst?

First 2-4 weeks on any dose
After each dose increase (e.g., going from 0.5 mg to 1 mg, or 1 mg to 2 mg)
When eating significantly less than usual (less food in = less stool out)
When not drinking enough water

Practical Relief: What Actually Helps

1. Fibre Up Strategically

Dietary fibre is your first line of defence. But the type matters:

Soluble fibre (oats, psyllium husk, legumes, rooibos, apples) absorbs water and forms a gel that softens stool
Insoluble fibre (whole grains, bran, leafy greens) adds bulk and speeds gut transit
Aim for 25-35g fibre per day. Most South Africans eat half this amount
Add fibre gradually — too much too fast worsens bloating

SA fibre tip: Oats porridge with ground flaxseed is an easy, affordable breakfast that adds 8-10g fibre per bowl. Add a side of stewed dried fruit (prunes, apricots) for a gentle natural laxative effect. Canned beans (chakalaka, baked beans) are cheap, widely available, and fibre-dense.

2. Hydration Is Non-Negotiable

On Ozempic you're eating less, so your natural fluid intake from food drops. You need to compensate by drinking more water. Aim for at least 8 glasses (2 litres) per day. Warm water or herbal teas (rooibos, ginger tea) can help stimulate gut movement. Avoid excess caffeine and alcohol as both dehydrate.

3. Move Your Body

Physical activity directly stimulates intestinal contractions. Even a 20-30 minute walk after meals can meaningfully improve bowel regularity. Yoga poses like twists and forward folds are particularly helpful for gut motility.

4. Establish a Routine

Your gut has a biological clock. Try to use the bathroom at the same time each morning, ideally 20-30 minutes after breakfast when the gastrocolic reflex is strongest. Don't ignore the urge when it comes.

Over-the-Counter Options Available in SA

Product	Type	How It Helps	Notes
Psyllium husk (Metamucil, Fybogel)	Bulk-forming fibre	Softens stool, adds bulk	Best long-term option; take with plenty of water
Movicol / Laxaday	Osmotic laxative	Draws water into colon	Gentle, safe for regular use under guidance
Lactulose syrup	Osmotic laxative	Softens stool	Available without prescription, may cause gas
Senokot (senna)	Stimulant laxative	Stimulates bowel contractions	Short-term use only; can cause dependence
Glycerin suppositories	Local lubricant	Immediate relief	For acute relief; not for daily use

Important: Always tell your pharmacist or doctor that you're on Ozempic/semaglutide before taking any laxative. Some laxatives affect absorption of other medications. Stimulant laxatives (Senokot, Dulcolax) should not be used regularly.

When Should You Call Your Doctor?

Most Ozempic-related constipation is uncomfortable but not dangerous. However, contact your healthcare provider promptly if you experience:

No bowel movement for more than 3-4 days despite trying remedies
Severe abdominal pain or cramping
Vomiting along with constipation
Blood in your stool
Fever accompanying gut symptoms
Signs of bowel obstruction (no gas passing, significant bloating, waves of pain)

These symptoms could indicate bowel obstruction or paralytic ileus, rare but serious complications that have been reported in some GLP-1 medication users.

Does the Constipation Ever Go Away?

Yes, for the vast majority of people. In clinical trials, GI side effects including constipation were most pronounced in the first 20 weeks and declined significantly thereafter. Many Ozempic users report their bowel habits return to near-normal once they've been on a stable dose for 2-3 months.

The key is not stopping the medication prematurely out of discomfort, but rather working with your doctor to manage side effects while your body adapts. A slower dose escalation schedule can significantly reduce GI symptoms for sensitive individuals.

Experiencing Other Ozempic Side Effects?

Get the complete guide to managing all semaglutide side effects, from nausea to hair loss.

Read the Complete Ozempic Side Effects Guide

Quick Reference: Constipation Relief Checklist

Drink 2+ litres of water daily
Eat 25-35g fibre per day (build up slowly)
Add psyllium husk to smoothies or porridge
Include prunes, dried figs or apricots in your diet
Walk 20-30 minutes daily, especially after meals
Establish a morning bathroom routine
Consider Movicol or lactulose if dietary changes aren't enough
Contact your doctor if no relief after 3-4 days

Medical disclaimer: This article is for information only and does not replace medical advice. If you are experiencing severe or persistent constipation on Ozempic, consult your doctor or pharmacist. Never stop your medication without medical guidance.