Side Effect – Constipation

Constipation: What it is, Symptoms & Treatment

Constipation is a common side effect of GLP-1 medications (such as Mounjaro and Wegovy) and is usually mild and manageable. This happens because these medicines slow down how quickly food moves through your digestive system. Most people find that symptoms improve as their body adjusts over time. Please do not stop your GLP-1 medication without speaking to your provider.

Symptoms of constipation can include:

• Fewer bowel movements than usual (often fewer than 3 per week)
• Hard, dry, or lumpy stools
• Straining or pain when opening your bowels
• A feeling that your bowel hasn’t fully emptied
• Abdominal discomfort or bloating

The risk of developing these symptoms is generally highest during the initial weeks of treatment and following dose increases, with symptoms usually improving as your body adjusts to the medication.

If you experience constipation, here are some tips to help:

• Dietary Recommendations:
• Increase fibre by eating more fruit, vegetables, beans, and wholegrains. Try and eat the recommended 30 grams of fibre each day, which can be challenging if you are not feeling hungry. You can try adding fibre, like psyllium husk, to your diet.
• Aim to drink plenty of water each day. At least 2-3 litres of water each day (8-12 cups) will help regulate the system
• Supplements and Medical Intervention

If constipation continues despite lifestyle and dietary changes, you may benefit from Laxatives:

• Bulk forming laxatives work by increasing or adding bulk or weight to stools, in return this stimulates bowel movement. Bulk laxatives include Fybogel (Ispaghula Husk and methylcellulose.
• Osmotic laxatives like lactulose or macrogol can take 2-3 days to see effect. They draw water from your body into your bowels to soften your stools and make them easier to pass.
• Stimulant laxatives, such as senna, bisacodyl and sodium picosulphate. These should be limited to maximum 3 days use. These can take up to 8 hours for relief. These stimulate the muscles that line your gut, aiding them to move stool along your back passage.
• Stool softeners can be used to allow water to pass into your stools to soften it and make it easier to pass. Stool softeners include Arachis Oil and Docusate.
• Suppositories like glycerin suppositories can help soften and lubricate the blockage so it passes more easily. These suppositories take 20-30 minutes to take action.

Which laxative should be used?

It is difficult to determine if a particular laxative will work better than another. Unless you have used a laxative before and are aware it works for you, please follow the guidance below:

1. Start with a bulk laxative
2. If your stools remain hard, you can switch to an osmotic laxative
3. If your stools are soft but still difficult to pass, try taking a stimulant laxative

If your constipation has not improved after taking laxatives for a week, speak to your GP

• Lifestyle adjustments:
• Regular physical activity (like walking) helps stimulate bowel movements. The recommended 150 mins a week can be achieved several ways. Visit the NHS live well pages for more information on how to achieve this: https://www.nhs.uk/live-well/ 
• Try to go to the toilet at a regular time each day, especially after meals
• Avoid delaying going to the toilet when you feel the urge

Follow the prescribed dosing schedule, as increasing doses too quickly may worsen side effects. If your symptoms become difficult to manage, a temporary pause in dose escalation or a reduction in dose may be appropriate. Please discuss any changes to your treatment with your provider before adjusting your medication.

For most patients, constipation is a temporary side effect that improves as the body adjusts to GLP-1 medication. Many people find that symptoms improve or resolve with appropriate dietary changes, increased fluid intake, and supportive self care measures.

GLP-1 related constipation often develops after starting treatment or following a dose increase. It may follow a predictable pattern linked to these changes. Keeping a food diary can help identify contributing factors and support symptom management.

Constipation does not affect the absorption or effectiveness of injected GLP-1 medications. However, if constipation persists, it may impact comfort, appetite, and overall wellbeing. If symptoms continue or worsen, please seek advice from your healthcare provider.

When to Seek Urgent Medical Advice

Please contact your GP or your local Out of Hours service as soon as possible if you experience:

• Constipation that is not improving despite following self care advice or treatment
• Constipation that lasts for more than 7 days
• Develop persistent or worsening abdominal (stomach) pain, swelling or bloating
• Blood in your stool
• Feel unusually tired or fatigued alongside ongoing constipation
• Notice a sudden change in your normal bowel habits

Call 999 or go to your nearest A&E immediately if you experience:

• Unexplained weight loss
• Unable to pass wind or have a bowel movement and are also vomiting
• Develop sudden, severe abdominal pain, especially if your abdomen is hard, swollen, or very tender to touch
• Severe abdominal swelling with worsening pain
• Notice black, tarry stools or a large amount of blood from your back passage
• Feel faint, collapse, or have symptoms of shock alongside severe abdominal pain

Important Safety Advice

It is important to use GLP-1 medications safely and in line with clinical guidance. Side effects can often be managed effectively when identified early and addressed appropriately.

Maintaining open communication with your provider is key to ensuring safe and effective treatment.

Remember:

• Do not ignore persistent or worsening symptoms
• Do not increase your dose without clinical advice
• If you have had a break in treatment, restarting at a lower dose may reduce side effects
• Ensure your GP is informed of any new or unusual symptoms

Additional support

If you are experiencing side effects or have any questions about your treatment, our clinical team is here to help.

If your symptoms are severe, worsening, or you feel they require urgent medical attention, please seek immediate advice from your GP, NHS 111, or attend your nearest A&E department if appropriate.

For all other queries:

• Book a free video consultation with one of our trained clinicians through our website. Appointments are available throughout the week, including daytime and evening sessions.
• Send us your question online using our form: https://forms.medicinemarketplace.com/251345635207050 A member of our clinical team will respond by email.
• Speak to us by phone by calling 0330 175 5747, and selecting option 3.

We are here to answer your questions and provide support throughout your treatment journey.

Written by: Uzma Dala MPharm (2238839)

Approved by: Shameela Adam MPharm (2070113)