There are a variety of different weight loss treatments, such as weight loss injections and tablets, that are licensed and approved for use in the UK. These treatments work best when taken alongside a healthy diet and exercise plan, so you can lose weight effectively and safely.

Weight loss medications are split into two categories: weight loss injections and weight loss tablets.

Weight loss injections

Weight loss injections help you to lose weight by reducing your appetite and helping you to feel more full after a meal. This means that you’ll be more satisfied after a meal with fewer calories. Weight loss injections are the most effective weight loss treatment for most people, and can help you lose up to 22.5% of your starting body weight (statistic taken from a study on Mounjaro 15mg taken once a week for 72 weeks).

Weight loss injections come as pens that you inject yourself with at home, so you do not need a medical professional to inject them for you. You usually inject yourself in the stomach, thigh, or upper arm (with help) – wherever is most comfortable for you.

Mounjaro (tirzepatide) is an injectable weight loss treatment. It contains the active ingredient tirzepatide which mimics 2 naturally occurring hormones in your body called glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP). They both help your body control your appetite and how full you feel. Mounjaro helps you lose weight by reducing hunger and prolonging how satisfied you feel after a meal.

Wegovy (semaglutide) is a weight loss injection that contains the active ingredient semaglutide, which acts like GLP-1. Usually, after you have eaten a meal, your intestines release GLP-1 to tell your brain that you have eaten. Wegovy works the same way and sends signals to your brain that you are full, so you can eat less and reduce your weight. Like Mounjaro, it also increases feelings of fullness after a meal.

Nevolat (liraglutide) is another injection for people to help them lose weight. It contains a different ingredient also mimicking GLP-1, called liraglutide. Like Wegovy and Mounjaro, liraglutide tells your brain you’re full, making it easier to eat less and lose weight with diet and exercise. It is injected once a day.

Saxenda (liraglutide) (currently out of stock) is another injection for people to help them lose weight. It contains a different ingredient also mimicking GLP-1, called liraglutide. Like Wegovy and Mounjaro, Saxenda tells your brain you’re full, making it easier to eat less and lose weight with diet and exercise. It is injected once a day. It’s currently long-term out of stock and we aren’t sure when it’ll be available again.

Weight loss tablets

Weight loss tablets help you lose weight in one of two ways: by reducing how much fat your body absorbs from food (orlistat and Xenical) or suppressing your appetite (Mysimba). Weight loss tablets are less effective than weight loss injections according to studies, but may be a good option if you are uncomfortable with injections.

Orlistat and Xenical contain the active ingredient orlistat. When taken with a meal that contains fat, it attaches to the enzymes in your digestive system, called lipase. Orlistat blocks lipase from breaking down fat in your food and absorbing it. This means some of the fat from your meal will turn into waste and be eliminated from your body as stool. alli is an over-the-counter weight loss tablet that also contains orlistat, but at a lower dose of 60mg.

Mysimba works differently than orlistat. Instead of having an effect on the digestive system, it works on the areas of your brain that control energy levels and food intake. This can reduce your appetite so that you feel fuller when you eat less. The combination of the 2 active ingredients in Mysimba can also control the pleasure you get from eating, reducing food cravings.

When you take any weight loss treatment, our doctors will review your weight regularly and make sure it is working as it should. Any weight loss medication must be taken alongside a healthy diet plan and regular exercise. Here at ZAVA, we send out a doctor and in-house nutritionist weight loss support pack with your first weight loss medication order. You can also access doctor advice for free through your patient account.

Each prescription weight loss medication works in a slightly different way, as they contain different active ingredients. Wegovy, Mounjaro, Saxenda and Mysimba all work on the brain and other organs, to reduce appetite levels and cravings, making it easier to eat less and lose weight.

Orlistat, alli, and Xenical work by changing how your body digests fat. alli is actually an over-the-counter weight loss pill, but a doctor or pharmacist still needs to check your BMI and medical history to make sure it’s suitable.

Weight loss treatment can have side effects, just like any other medication. Not everyone will get them and if they do appear, they usually only last for a few weeks. If you get side effects whilst taking weight loss treatment and they do not go away or bother you a lot, you can speak to our doctors.

Some treatments are increased gradually over time, like Wegovy, Mounjaro and Mysimba, to reduce the chances of side effects. You can find the full list of known side effects in the patient information leaflet that comes with your treatment pack.

Common Wegovy side effects

The most common side effects of Wegovy are:

• headaches
• feeling sick / being sick
• diarrhoea
• constipation
• stomach pain
• feeling weak or tired

The side effects usually go away over time.

Common Mounjaro side effects

Very common side effects of Mounjaro are:

• diarrhoea
• constipation
• feeling sick (nausea) and vomiting
• when used in combination with certain diabetes medications: low blood sugar

Side effects that affect the digestive system are usually not severe. They mostly show up after starting the treatment or after increasing the dosage – once the body gets used to the medication these side effects usually disappear.

Common Mysimba side effects

Common Mysimba side effects include:

• hot flushes
• anxiety
• trouble sleeping
• headaches
• dizziness
• restlessness
• heart palpitations

These usually go away once your body gets used to the medication. You cannot take Mysimba if you have certain medical conditions, but our doctors will check your suitability before prescribing.

Common orlistat, alli, and Xenical side effects

The most common side effects of orlistat, alli, and Xenical are:

• needing to poo urgently and more frequently
• oily or fatty poo
• oily discharge from your rectum (anus)
• flatulence (farting)

Sticking to a low fat diet will decrease the risk of these side effects.

You can get some weight loss medications over the counter, but they don’t usually contain an active ingredient. An exception to this is alli, which contains orlistat but at a lower dose of 60 mg per tablet. That being said, you can only take weight loss medication if you meet certain conditions and some treatments cannot be taken if you take other medications or have certain health conditions.

So, even if you want to take alli, a pharmacist or doctor will need to check your medical history and BMI first. Our doctors will make sure it is safe to take any weight loss medication before you are prescribed it.

Alongside medication, you can support your weight loss journey with options like healthy eating and regular exercise. Surgery is sometimes considered when other weight loss methods haven’t worked and should generally be a last resort.

Diet

To lose weight at a safe pace of 0.5 to 1 kg a week, you should reduce your calorie intake by 600 kcal a day. Your doctor will help you with a diet plan if you need it. This is not about following a ‘fad’ diet, but about making healthier long lasting choices that will improve your eating habits for the rest of your life.

For women, weight loss can be achieved by consuming no more than 1,400 calories a day. Men should be eating no more than 1,900 calories daily. To lose weight, you should swap high-energy and unhealthy foods for healthier choices. This means lowering your intake of processed food, fast food, and sugary drinks like sodas and alcohol.

Exercise

Although a healthy and balanced diet can help you to lose weight, you also need to burn energy through regular exercise. The UK government recommends that adults do at least 150 minutes of moderate intensity exercise weekly. This can be split into 30 minute sessions 5 times a week. Some exercise is better than none, so if you struggle to exercise, you can increase this slowly, starting with 10 minutes a day.

Exercise has many health benefits and can reduce the risk of other illnesses that can affect your weight. According to the NHS, regular exercise can reduce the risk of getting type 2 diabetes by up to 30%.

Surgery

Weight loss surgery can sometimes be used as a treatment for obesity. It is only available through the NHS if you are severely obese and:

• are fit enough to have surgery
• have a BMI over 40, or between 35 and 40 and certain health conditions that weight loss could improve, such as type 2 diabetes
• are committed to the long term follow up of your surgery
• you have tried all other weight loss strategies but they have not achieved or maintained weight loss
• are receiving intensive management of your weight, usually through your GP

In rare cases, surgery may be recommended straight away if you have a BMI over 50.

People can’t take GLP-1 agonists like semaglutide and other weight loss injections if they have existing health conditions that make them unsafe.

Weight loss injections may not be safe for:

• people taking certain medications, such as diabetes medicines (including insulin) and immunosuppressants
• pregnant or breastfeeding women
• those with pancreatic disorders, such as pancreatitis
• those with a history of thyroid cancer
• those with a history of gallbladder disease