Orlistat is the only licensed drug in the UK for weight loss. It’s designed to be used by people with a BMI over 30 as part of a weight loss management plan. The active ingredient works by blocking fat-absorbing enzymes, but for it to be effective, it must be used alongside exercise and a healthy, low-fat diet.

How do orlistat tablets work?

Orlistat works by attaching itself to enzymes in your gut, known as lipases. These enzymes are responsible for breaking down fat, so it can be absorbed into the body.

By interfering in this process, orlistat can prevent up to 30% of the dietary fat you eat from being absorbed and making their way into your cells. The undigested fat then passes through the gastrointestinal system and leaves the body as waste (faeces).

For it to work, you must carefully control your calorie intake and how much fat you eat.

When is orlistat prescribed?

If your BMI is over 30 and you’ve already tried other ways to lose weight, then your doctor may prescribe orlistat tablets. Treating obesity in this way is sometimes used in patients with a BMI over 28 if they also suffer from:

  • high blood pressure
  • cholesterol
  • type 2 diabetes

BMI is your body mass index. It’s a calculation of how healthy your weight is based on your height and mass (how much you weigh). Anything between 30 and 39.9 is considered to be obese, and a reading over 40 is severely obese.

You can work out your BMI using the NHS healthy weight calculator.

How effective is Orlistat Xenical?

Some experts believe that weight loss medication can help people lose up to 50% more weight than dieting alone. So, for example, if you can lose 6kg by dieting and exercising regularly, then you could lose as much as 9kg using orlistat as well.

It’s important to remember that losing weight is a gradual process and you won’t see results straight away. Your doctor or pharmacist will monitor your weight loss carefully.

If you’ve lost weight at the end of the first 12 weeks, then it’s highly likely that orlistat will continue working for you. However, if you don’t meet your weight loss target (usually 5% of your body weight), then your doctor may recommend that you stop taking orlistat.

To lose weight effectively, orlistat must be taken as part of a calorie-controlled diet.

How to take orlistat tablets

To balance your rate of fat absorption, you should spread your calorie intake evenly throughout the day. Each meal should contain no more than 30% fat – so of 1000 calories, around 300 of these should come from dietary fat.

One orlistat (120mg) tablet should be taken with each meal (three times a day). If you miss a meal or you eat a meal without fat in it, then we recommend skipping your dose of orlistat and taking it as normal at your next main meal.

Not sticking to a low-fat diet can increase your chances of experiencing some unpleasant side effects. The most common side effects of orlistat include:

  • fatty/oily stools
  • oily discharge
  • changes in your bowel movements
  • flatulence
  • abdominal pain, bloating, or discomfort

In rare circumstances, orlistat can cause an allergic reaction. If you experience a rash, trouble breathing, or swelling of the face, tongue or throat, seek immediate help.

Orlistat can stop you absorbing vitamins A, D, E, and K, so we recommend taking a multi-vitamin every day to make up for any nutrients lost.

You can find more detailed instructions on how to take orlistat in the patient information leaflet that comes with it.

Getting the most from orlistat

The effectiveness of Orlistat Xenical is dependent on a healthy diet and regular exercise. To get the most out of orlistat, we recommend making the following changes:

  • reduce your daily intake of fat, such as dairy and sugary foods
  • eat a well-balanced diet rich in fruit and vegetables
  • exercise for at least 30 minutes between three and five times a week
  • don’t skip meals and eat slowly to keep hunger at bay
  • cut down on your stress levels and take some time out

You’re more likely to lose weight and keep the weight off, if you adopt a healthy lifestyle and stay positive. Keep your goal in mind and focus on the progress you’re making.

measuring waist

Can you buy Orlistat Xenical?

Orlistat Xenical (120mg) is a prescription-only medication. Your doctor can prescribe it or you can buy it privately via an online pharmacy, like Post My Meds.

There are two drugs licensed in the UK for treating obesity, and both contain the same active ingredient – orlistat.

Orlistat Xenical – this is the branded version of orlistat. Prices start from £34.99 for a two weeks’ supply (42 capsules).

Orlistat (generic) – is an unbranded alternative to Xenical, and prices start from £17.49 for the same two week’s supply.

Before you can buy orlistat online, you must fill out a short online consultation. The information you provide is reviewed by a registered pharmacist who checks to make sure that it is safe for you to take this medication.

There are some risk factors that can prevent you from taking orlistat. If you are pregnant, breast-feeding, or allergic to any of the items contained in this medicine, you should tell your doctor or pharmacist.

Taking the next steps

If your BMI is over 30 and you’ve tried to diet, exercised regularly and exhausted all other options then Orlistat Xenical might be what you need to reach your weight loss target.

For it to work effectively, you’ll need to stick to a low-fat diet and stay active, but if you do all this then Xenical could help you lose up to 50% more weight.

You can get Orlistat Xenical or its unbranded alternative – orlistat – from your GP. You can also buy it online from a private pharmacy, like Post My Meds.

Delivery is free and everything is sent in plain, unbranded packaging to protect your privacy. The only thing you can expect to see on the box is your name and address.

Although all of our content is written and reviewed by healthcare professionals, it should not be substituted for or used as medical advice. If you have any questions about your health, please speak to your doctor.

Authored Sep 08, 2021 by Joseph Issac, MPharm
Reviewed Sep 08, 2021 by Prabjeet Saundh, MPharm