Each weight loss treatment has its own set of potential side effects, depending on the active ingredient. Most side effects are temporary and should go away within a few days of taking the medication, although they can sometimes last longer. If the side effects persist or cause significant discomfort, it's important to consult with your doctor.

Common side effects of weight loss treatments include:

• Abdominal pain
• Diarrhoea or constipation
• Headache
• Nausea or vomiting
• Taste changes
• Fatigue
• Possible risk of gastroparesis (delayed gastric emptying)

For a complete list of side effects, refer to the medication's packaging.

It's important to note that everyone responds to medications differently, and rapid weight loss can also cause side effects like skin changes (such as stretch marks) or irregular periods.

How long do side effects last? Most side effects should subside within a week of starting the medication, but this varies by individual. Medications like Saxenda or Mysimba are initially taken at a lower dose, which is gradually increased to reduce common side effects like nausea or vomiting.

What to do if you experience side effects: If side effects occur, you can manage some of them at home. For nausea and vomiting, try smaller meals that are not greasy, spicy, or fatty, and stay hydrated. Over-the-counter painkillers like paracetamol can help with headaches.

For orlistat and Xenical, you may experience oily stools and an increased urge to use the toilet. Reducing fat intake and spreading it throughout the day can help minimize these side effects. If symptoms persist, your doctor may adjust your dosage.

Most side effects will resolve naturally, but if you experience serious reactions, such as an allergic reaction, seek immediate medical attention by calling 999 or going to A&E.

To access prescription weight loss treatment, you generally need to have a BMI over 30, or a BMI over 27 or 28 if you have certain medical conditions, such as diabetes. This requirement varies depending on the specific medication. Weight loss treatments may not be safe or effective unless you're overweight or obese, so it's essential to consult with a doctor before starting treatment.

Certain medical conditions or medications can interact with weight loss treatments, making them less effective or even unsafe. Always be honest and accurate with your doctor about your health and current medications, as weight loss medications can cause severe side effects if not suitable for you.

Do you need a certain BMI to get weight loss treatment? Yes, typically you need a BMI over 27 or 28 to use weight loss treatments, especially if you have a related medical condition. If you have a BMI of over 30, you can qualify for treatment even without a medical condition.

If you're unsure of your BMI, use a BMI calculator to check.

Contraindications Certain health conditions may make weight loss treatments unsuitable. It's important to consult a doctor if you have:

• Liver or kidney issues
• Inflammatory bowel disease (IBD)
• Thyroid disease
• Heart problems
• Epilepsy or a history of seizures
• Anxiety or other mental health conditions
• Chronic malabsorption syndrome (difficulty absorbing nutrients)

Weight loss treatment is also not recommended for those under 18, pregnant or breastfeeding individuals, or anyone allergic to the medication ingredients.

Medications that may interact with weight loss treatment: Some medications can affect the effectiveness of weight loss treatments or pose safety risks. Speak to your doctor if you take any of the following:

• Epilepsy medication
• HIV treatment
• Mental health medications
• Heart medication (e.g., amiodarone)
• Blood thinners (e.g., warfarin)
• Hypothyroidism treatments (e.g., iodine salts)
• Diabetic treatments
• Parkinson's disease medication (especially monoamine oxidase inhibitors)
• Opiates
• Steroids
• Malaria treatments
• Antibiotics
• Asthma treatments (e.g., theophylline)

Prescription weight loss treatments can aid in weight loss, but they should be combined with regular exercise and a healthy, balanced diet. In some cases, weight loss surgery may be an option, although it is typically a last resort.

Exercise

Exercise helps with weight loss by burning calories. When you eat, your body stores energy as fat, and if you consume more calories than you burn, weight gain occurs. Physical activity burns this stored energy and helps manage conditions like diabetes. Regular exercise is essential for losing and maintaining a healthy weight.

The NHS recommends 150 minutes of moderate-intensity exercise per week, which could include activities like dancing, cycling, or power walking. Alternatively, 75 minutes of higher-intensity exercise (such as running or circuit training) can also be effective. Combining both moderate and high-intensity exercises is ideal for weight loss. Additionally, focus on balance and strength exercises twice a week, such as using weights or practicing yoga and tai chi.

Superdrug Online Doctor offers advice on exercise as part of its weight loss services.

Diet

A healthy diet is crucial for weight loss. The NHS suggests reducing your calorie intake by 600 calories per day. For women, this typically means consuming no more than 1,400 calories daily, and for men, no more than 1,900. To maintain a balanced diet, focus on incorporating the following:

• Fruits and vegetables
• Healthy fats (e.g., avocado)
• Whole grains
• Nuts, beans, and natural yogurt

Limit or avoid:

• Sugary foods and drinks (e.g., sweets and chocolate)
• High-fat foods, especially those with saturated fats
• Fried or oily foods
• Crisps, white bread, and alcohol

For a balanced diet, include plenty of fruits and vegetables, some protein (like meat, fish, and eggs), dairy, whole grains (e.g., rice, potatoes), and minimal amounts of unhealthy fats and sugars.

Surgery

Weight loss surgery is typically a last resort for individuals who have struggled with other treatment methods. The most common types of surgery include:

• Gastric band: A band around the stomach reduces the amount of food needed to feel full.
• Gastric bypass: The stomach is connected to the small intestine, reducing calorie absorption and making you feel fuller with less food.
• Sleeve gastrectomy: Part of the stomach is removed, which limits food intake.

These surgeries help by reducing stomach size, so you feel full after eating smaller portions. However, it’s important to maintain a healthy diet to ensure proper nutrition after surgery.

You may be eligible for weight loss surgery if you are:

• Severely obese with a BMI over 40
• Obese with a BMI over 35 and related medical conditions
• Have a BMI over 50, in which case surgery may be available immediately

Although weight loss surgery is generally safe when recommended by a doctor, it comes with risks and is not suitable for everyone. It may not be available through the NHS for all candidates.

• Mysimba 8mg/90mg Prolonged-Release Tablets (2021) EMC (accessed 03 May 2022)
• Obesity (2019) NHS (accessed 03 May 2022)
• Saxenda 6mg/mL Solution for Injection in Pre-Filled Pen (2021) EMC (accessed 03 May 2022)
• Weight Loss Surgery (2020) NHS (accessed 03 May 2022)
• Xenical 120mg Hard Capsules (2017) EMC (accessed 03 May 2022)
• Mounjaro (2023) EMC (accessed 15 February 2024)