Weight loss injections like Mounjaro, Wegovy, and Ozempic are significantly transforming obesity management, offering powerful support for sustainable weight loss. But like many effective treatments, these weight loss solutions also come with gastrointestinal (GI) side effects—constipation being one of the most common.
In this guide, we will break down why constipation happens with weight loss drugs and share practical ways to treat constipation effectively while staying on track with your health goals.
Why does constipation happen with weight loss medications?
GLP-1 receptor agonists such as semaglutide (Wegovy and Ozempic) and trizepatide (Mounjaro) mimic the body’s natural hormones, which regulate appetite and insulin secretion. Constipation on weight loss drugs occurs due to one of the key mechanisms of weight loss medications, which is slowing gastric emptying. Unfortunately, this same effect also delays the movement of food and waste along the digestive tract, which can result in sluggish bowel movements and constipation.
According to a 2022 review, gastrointestinal side effects, including constipation, were among the most commonly reported adverse effects of GLP-1 receptor agonists, especially during the dose-escalation phase in about 25-35% of users.
Constipation on weight loss drugs: Who is most affected?
While digestive issues with weight loss medications can affect anyone, certain factors may increase your likelihood of experiencing them.
New to weight loss drugs
Gastrointestinal side effects, including constipation, are often more severe during the first few weeks or after an increase in dose as your body is adjusting to the medicine.
Low fiber and fluid intake
Fiber adds bulk to stool, and fluid makes it soft and easier to pass. Reducing fluid or fiber intake while on GLP-1s disrupts bowel regularity.
Sedentary lifestyle
Intestinal contractions are stimulated by physical activity. If you have an inactive lifestyle, the digestive system slows down, worsening GI problems.
History of constipation
If you have a medical history of irritable bowel syndrome with constipation (IBS-C), hypothyroidism, or other motility disorders, the medications may exacerbate symptoms.
Taking other medications
Drugs like opioids, iron supplements, or certain antidepressants, when combined with GLP-1s can further reduce gut motility.
Skipping meals
Eating too little or skipping meals while on weight loss drugs can reduce the natural triggers for bowel movements.
Wegovy constipation remedies
Wegovy (semaglutide) is an effective weight loss injection, but users often experience constipation during the dose-escalation phase. A few consistent strategies can help manage this.
- Boost natural fiber intake by including leafy greens, lentils, and whole grains
- Do not skip meals or fast for extended periods, as it further slows digestion
- If necessary, consider a gentle osmotic laxative
- Incorporate light physical activity for 20-30 minutes a day
Note: Wegovy and Ozempic both contain semaglutide, so many remedies for one work for the other. However, the dosing may influence how the body responds.
Mounjaro constipation help
Mounjaro (tirzepatide) is a dual agonist of GIP and GLP-1 receptors, highly effective for blood sugar control and weight loss. However, this dual action can intensify gastrointestinal issues;
- Magnesium citrate is an osmotic laxative that can provide short-term relief from constipation, but should only be used occasionally and under the guidance of a pharmacist.
- Regular physical activity of 20-30 minutes promotes gut motility and is particularly important for those with sedentary jobs.
- Include probiotic-rich foods such as kefir, yogurt, or kimchi to help restore a healthy balance of gut bacteria, supporting bowel function.
A 2023 systematic review noted that gastrointestinal side effects like constipation, nausea, and diarrhoea were more prevalent during the dose-escalation phase of tirzepatide, particularly in individuals who had pre-existing digestive sensitivities.
Ozempic and constipation relief
Due to the medication’s mechanism of slowing gastric emptying, constipation can occur as a common side effect because of the delayed bowel movements.
- Aim for at least 2 litres of water daily. Adequate hydration softens stool and supports regular bowel movement.
- Establish a regular bathroom routine, preferably 20-30 minutes after meals—when the digestive system is the most active.
- The NICE guidelines recommend bulk-forming laxatives such as Fybogel (ispaghula husk) for chronic constipation.
These are one of many constipation tips for GLP-1 users, which can help them continue their weight loss journey while keeping in mind safety measures.
Best laxatives for weight loss medications
The following laxatives are commonly used with weight loss injections;
| Laxative type | Example | Use |
| Osmotic | Lactulose | For dry stools |
| Bulk-forming | Ispaghula husk | Gentle, daily use |
| Stimulant (short-term) | Senna, Bisacodyl | Not for daily use |
Note: Always consult a healthcare professional before combining laxatives with GLP-1 drugs.
Other digestive issues with weight loss drugs
While constipation is a well-known side effect of GLP-1 receptor agonists, other gastrointestinal symptoms may include;
- Nausea
- Vomiting
- Bloating
- Diarrhoea
- Gastric reflux
These symptoms subside as your body adjusts to the dosage of weight loss injections. However, if symptoms persist, speak to your healthcare provider, and they may recommend dose adjustments.
When to seek medical advice
While constipation is a common side effect of weight loss medication, it is essential to recognise when it may indicate a more serious issue.
Contact your health care provider or visit Batley Pharmacy if you experience;
- Fever or signs of infection
- Severe abdominal pain
- Unexplained weight loss
- No bowel movement for more than 5 days
- Blood in stools
- Bleeding during bowel movements
These symptoms can be serious and may indicate complications such as gastrointestinal bleeding, bowel obstruction, or other conditions that require immediate medical evaluation.
Final thoughts
From adjusting your fiber intake to selecting appropriate laxatives, understanding how to alleviate your symptoms associated with weight loss injections is crucial for the effectiveness of your weight loss journey.
If you are considering weight loss injections, Batley Pharmacy offers a comprehensive consultation process to determine your eligibility, conducting an initial assessment of your health status and medical history to ensure weight loss injections are suitable for you. Visit or call us for a consultation, and our experts will provide personalised advice tailored to your needs.
