Starting a weight loss injection can feel like a big step, especially if you have heard stories about stomach side effects. Many patients want to know what to expect, and one of the most searched concerns is Mounjaro diarrhoea. Nausea and fatigue are also common topics, particularly in the early weeks.
Regulated weight loss treatment is available at The Care Pharmacy, with professional advice and continued support throughout. This comparison explains how Wegovy and Mounjaro side effects can differ, why symptoms happen, and what you can do to manage them. Get in touch now to explore your options, or start an online consultation form to review your suitability.
Both Wegovy and Mounjaro support appetite regulation and increase feelings of fullness. They slow stomach emptying and change how digestion works. This can help reduce hunger, but it may also cause nausea, diarrhoea, constipation, or bloating.
Side effects are often most noticeable when treatment begins or when the dose increases. Symptoms often improve for many patients once the body settles, especially with smaller portions and reduced fat intake.
Mounjaro diarrhoea can happen because the medication affects digestion and appetite signals. Some patients notice mild symptoms for a short period, while others may feel more discomfort. For many people, diarrhoea settles once routines become consistent.
Symptoms may be worse when meals are large, greasy, or eaten quickly. Skipping meals and overeating later can also trigger digestive issues. Hydration is important, especially if symptoms last more than a day or two.
If symptoms feel difficult to manage, get in touch with our team for guidance or start an online consultation form for a review.
Wegovy can also cause digestive side effects, especially nausea. Some patients find Wegovy nausea is more noticeable than diarrhoea, while others experience a mix of symptoms. Side effects often appear early and may improve over time.
Wegovy dosing increases gradually, which can help improve tolerability. Smaller meals, steady hydration, and avoiding rich foods often make symptoms easier to manage.
Nausea can happen with both medications, and experiences vary. Some patients report mild nausea, while others find it affects appetite and daily routine. Nausea may be more noticeable if you eat too quickly or choose very rich meals.
Nausea often feels easier to manage when meals are spaced throughout the day and portion sizes are reduced. Simple foods and slow eating can help during the adjustment period.
Fatigue is another side effect some patients notice, especially at the beginning. Appetite often drops, calorie intake reduces, and the body adjusts to new routines. This can leave some people feeling low in energy for a short time.
Fatigue often improves with hydration, balanced meals, and better sleep. Once the body adapts and results become more consistent, many patients feel more balanced again.
Digestive side effects can often be reduced with practical changes. The goal is to support your body while it adjusts, rather than pushing through discomfort without a plan. Small changes can make treatment feel much more manageable.
A balanced diet is one of the simplest ways to help manage side effects on weight loss medications, and is also essential for helping you progress towards your weight loss goals. Need dieting inspiration? Check out our TikTok below:
@thecarepharmacyuk When the ‘diet’ looks better than the takeaway menu! Thanks @AndysWGVYjourney for sharing! ##healthyrecipes #HealthyLifestyle #Food #MealPrep ♬ original sound – TheCarePharmacy
Start an online consultation form to review your options, or get in touch with our team if you need tailored support.
The comparison below outlines the main side effects linked to Mounjaro and Wegovy, including digestive changes and tiredness. It also includes simple support tips that may help make treatment easier to tolerate while your body adjusts.
| Side Effect | Mounjaro | Wegovy | What Can Help |
|---|---|---|---|
| Diarrhoea | Can occur, often linked to meal size and fat intake | Can occur, sometimes less common than nausea | Lower fat meals, hydration, smaller portions |
| Nausea | Common, often early or after dose increases | Very common, especially early in treatment | Smaller meals, bland foods, slow eating |
| Fatigue | Possible, often linked to reduced intake | Possible, especially during adjustment | Hydration, sleep, balanced meals |
| Appetite reduction | Often strong and noticeable | Often steady and consistent | Structured meal planning and protein focus |
There is no single answer, because side effects depend on your body, your dose, and your routine. Some people find Mounjaro diarrhoea is their main issue, while others find nausea more noticeable. Mild side effects are common for many patients and often improve within the first few weeks.
What matters most is having regulated access and support if side effects feel difficult. At The Care Pharmacy, we guide patients through treatment with clear advice and professional review when needed.
Mounjaro diarrhoea, nausea, and fatigue can happen, especially when starting treatment or increasing dose. Smaller meals, lower fat foods, and consistent hydration can help improve symptoms for many patients. Wegovy can cause similar effects, with nausea often reported more frequently.
Trusted, regulated weight loss support is available at The Care Pharmacy, so start an online consultation or get in touch to discuss your options with professional care.
This blog was written in collaboration with Pharmacy Mentor.
Medically reviewed by
Superintendent Pharmacist
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