Top 5 Common Weight Loss Medication Side Effects & How to Minimise Them
If you’re considering or currently using weight loss medications, you’re not on your own. From injectable treatments like Ozempic and Mounjaro, to oral appetite suppressants, these medications are helping thousands achieve their goals. But while they can be effective, they can also come with side effects that you need to be aware of. At Bold Street Clinic, transparency is key. We believe informed choices lead to better outcomes.
This blog explores the five most common weight loss medication side effects, why they occur, and how you can minimise them through proper medical guidance, hydration, and a nutritional diet. Whether you’re researching treatments or already taking them, this guide helps you stay on track safely.
What are the most common weight loss drugs’ side effects?
Weight loss drugs work in various ways, often by suppressing appetite or altering the way your body processes food. This can affect your gastrointestinal system, energy levels, and even your hair and skin. Let’s explore the top five side effects reported by patients in the UK.
1. Nausea & Vomiting
Why it happens
Many weight loss injections, particularly GLP-1 receptor agonists like Ozempic, slow gastric emptying. This can cause food to sit in your stomach longer, leading to nausea or vomiting.
How to minimise it:
- Eat smaller meals more frequently
- Avoid greasy or rich foods
- Don’t lie down immediately after eating
- Stay hydrated with water and herbal teas
Tip
Start with a low dose as advised by your doctor to allow your body to adjust.
Did you know?
Clinical studies have shown that up to 44% of patients on GLP-1 medications experience some degree of nausea in the first few weeks. Most cases subside over time, especially when doses are increased gradually.
2. Diarrhoea or constipation
Why it happens: These seemingly opposite symptoms are both common as your digestive system adjusts to changes in appetite, food intake, and gut motility.
How to minimise it
- For constipation: Increase fibre (vegetables, oats), drink more fluids, stay active
- For diarrhoea: Avoid dairy and artificial sweeteners, eat binding foods (rice, banana)
Speak to your practitioner before taking any over-the-counter laxatives or anti-diarrhoeals.
3. Fatigue or headaches
Why it happens
A sudden reduction in food intake or dehydration can cause low blood sugar levels or electrolyte imbalances, resulting in fatigue or headaches.
How to minimise it
- Maintain balanced meals, including protein and healthy fats
- Don’t skip meals or fast without supervision
- Ensure adequate hydration (1.5–2 litres/day)
- Consider a multivitamin if recommended
Related reading: Your Guide to Long-Term Weight Loss & Nutrition
4. Hair Loss
Why it happens
Hair thinning can occur due to nutrient deficiencies, hormonal changes, or rapid weight loss. It’s more common than you think and usually temporary.
How to minimise it
- Eat a varied diet rich in iron, zinc, and biotin
- Add collagen supplements or protein shakes if approved by your clinician
- Prioritise stress management and adequate sleep
Pro tip: Ask your healthcare provider about blood testing to check for iron or thyroid issues if hair loss continues beyond three months.
At Bold Street Clinic, we offer tailored plans to support your overall well-being, including skin and hair health.
5. Dehydration and dry mouth
Why it happens
Vomiting, diarrhoea, or reduced food intake can cause fluid and electrolyte loss.
How to minimise it
- Carry a refillable water bottle
- Add electrolytes (sugar-free) if experiencing frequent vomiting or diarrhoea
- Limit caffeine and alcohol
Dehydration is one of the most overlooked weight loss medication side effects, yet one of the easiest to prevent.
Suggested add-on: Try adding fruits like watermelon or cucumber to your meals for hydrating benefits that also offer fibre and nutrients.
When to seek medical help
While most side effects are manageable, some require medical attention:
- Severe or persistent abdominal pain (possible pancreatitis)
- Yellowing of the skin or eyes (sign of gallstones)
- Vision changes in diabetics (possible retinopathy)
- Signs of bowel obstruction (no bowel movement, severe cramping)
If any of these occur, contact your prescribing clinician or seek emergency care.
Learn more here: Harvard Health on GLP-1 Side Effects
Lifestyle tips to support your medication
Adjust your diet
- Avoid greasy or sugary foods
- Eat small, protein-rich meals
- Incorporate plenty of vegetables and fibre
Stay active
- Daily walks support digestion and energy levels
- Light resistance training helps maintain muscle mass
Don’t skip support
- Weight loss injections are more effective when combined with coaching and accountability
- We offer one-to-one weight loss coaching for sustainable results
Learn more about Personalised Weight Loss Coaching.
Why choose Bold Street Clinic for your weight loss journey?
- Doctor-led treatment with a focus on safety and transparency
- Access to both medication and nutritional guidance
- Located in central Liverpool, serving clients across Merseyside
- Supportive, friendly environment with real results
Bonus: Our expert team conducts regular check-ins to track your progress, adjust your plan, and ensure side effects are managed properly.
Read: Weight Loss Treatments in Liverpool: Why Bold Street Clinic Is Your Best Choice
Be informed, be empowered
Experiencing weight loss drug side effects doesn’t mean the medication isn’t right for you. With the right support system, you can manage most symptoms and continue towards your health goals. At Bold Street Clinic, we ensure you’re never alone on your journey.
f you’re considering a weight loss solution, book a consultation today and get a personalised assessment.
