Xenical / Orlistat
Orlistat 120mg — branded as Xenical or supplied as generic orlistat.
Xenical and generic Orlistat are prescription-only weight-loss medicines. The usual dose is one 120mg capsule with each of your three main meals per day. They work by reducing how much fat you absorb from food. They are used alongside an active lifestyle and a calorie-controlled balanced diet; exercise helps you maintain a healthy weight when you stop treatment.
Part of our weight loss treatment planThis page provides factual information about Xenical and Orlistat (orlistat) for educational purposes. This is not an advertisement. A prescription will only be issued following a successful clinical assessment by our healthcare team.

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Frequently asked questions about Xenical and Orlistat
What is Xenical / generic Orlistat?
Xenical is the branded 120mg orlistat capsule; generic orlistat contains the same active ingredient at the same strength. Both are used alongside a calorie-controlled diet and exercise to help you lose weight. Exercise and a balanced diet also help you maintain a healthy weight when you stop taking your medication.
How does Orlistat / Xenical work?
Xenical and generic Orlistat contain the active ingredient orlistat at 120mg per capsule. They are prescription-only medicines that work in your digestive system by preventing about a third of the fat in each meal from being digested. They attach to the enzymes that usually break down fat; any undigested fat passes out of your body when you go to the toilet. They do not work through the brain's appetite centres in the same way as some other weight-loss medicines.
In many clinical trials, when taken with diet and exercise, orlistat has been shown to support greater weight loss than diet and exercise alone.1
How much does Xenical or Orlistat cost?
Generic Orlistat packs start from £44.99. Branded Xenical is typically priced higher than generic orlistat. Pack sizes are usually 84 or 168 tablets.
Xenical cost and packs Orlistat cost
* prices displayed are for generic products, branded will be more
Is Xenical/Orlistat suitable for me?
If you are overweight, Xenical or Orlistat can aid weight loss when used alongside a calorie-controlled diet and exercise. They can be particularly helpful if you have previously found it difficult to lose weight with diet and exercise alone. When combined with a healthy diet and exercise you could lose around 1kg (2lb) more for every 2kg (4lb) you lose from dieting alone.
How do I take Xenical/Orlistat?
The usual dose is one 120 mg capsule taken with each of your three main meals per day. You can take it immediately before, during or up to one hour after a meal.
To support effective, long-lasting results, combine Xenical/Orlistat with exercise and the right diet. You need a balanced, calorie-controlled diet rich in fruit and vegetables, with no more than about 30% of calories from fat. Carbohydrate, protein and fat should be spread evenly across your three daily meals, and you should try to avoid fat-containing snacks such as biscuits, chocolate or crisps between meals.
If you miss a meal or have a meal with no fat, you do not need a dose, as the medicine only works when there is fat in your meal.
If you miss a dose you can take it within an hour of your meal, but do not take a double dose.
Tell us if, for any reason, you have not taken your medicine exactly as prescribed. Otherwise we may think it was not effective or well tolerated and may change your treatment unnecessarily. We will usually discontinue treatment after 12 weeks if you have not lost at least 5% of your starting body weight.
You should take a daily multivitamin supplement alongside Xenical/Orlistat. Some vitamins and minerals are fat-soluble; if you do not digest all the fat in your diet you could become deficient.
What information do you need to know about me?
Our advice is to read the information on obesity and, when you feel ready, complete a confidential consultation with one of our doctors. Give as much detail as you can so we can assess your condition safely.
We will only prescribe Xenical/Orlistat when it is safe to do so and in your best interests.
Xenical/Orlistat is not suitable for children, or for women who are pregnant or breastfeeding. It is also not suitable if you have certain problems with food absorption or reduced bile flow.
You must tell us about all medicines you use, including prescribed, over-the-counter and supplements, because some can interact with Xenical/Orlistat.
What are the possible side effects of taking Xenical/Orlistat?
As with all medicines, Xenical/Orlistat can cause side effects, although not everyone gets them. You may notice changes to your bowel movements because more fat passes through your digestive system. These changes are often mild and most common in the first few weeks. Typical symptoms can include increased wind, more frequent bowel movements and oily discharge. If you eat meals higher in fat than the recommended limit, you may find bowel control harder. Over time, symptoms often reduce, especially if you follow the recommended diet.
Always tell a doctor or pharmacist as soon as possible if you do not feel well while you are taking Xenical/Orlistat.
Very common side effects (affects more than 1 user in 10)
- Headache
- Abdominal pain or discomfort
- Urgent or increased need to open the bowels
- Flatulence (wind) with discharge
- Oily discharge, oily or fatty stools
- Liquid stools
- Low blood sugar levels (experienced by some people with type 2 diabetes)
- Upper respiratory infections
- Flu (influenza)
Common side effects (affects 1 to 10 users in 100)
- Rectal pain or discomfort
- Soft stools
- Incontinence (stools)
- Bloating (experienced by some people with type 2 diabetes)
- Tooth or gum disorders
- Irregularity of menstrual cycle
- Tiredness
- Anxiety
- Lower respiratory infections
- Urinary tract infections
The following side effects have also been reported but their frequency cannot be estimated from the available data:
- Allergic reactions. The main symptoms are itching, rash, wheals (slightly elevated, itchy skin patches that are paler or redder than surrounding skin), severe difficulty in breathing, nausea, vomiting and feeling unwell
- Skin blistering (including blisters that burst)
- Diverticulitis
- Bleeding from the back passage (rectum)
- Increases in the levels of some liver enzymes may be found in blood tests
- Hepatitis (inflammation of the liver). Symptoms can include yellowing skin and eyes, itching, dark coloured urine, stomach pain and liver tenderness (indicated by pain under the front of the rib cage on your right-hand side), sometimes with loss of appetite. Stop Xenical/Orlistat if such symptoms occur and tell your doctor
- Gallstones
- Pancreatitis (inflammation of the pancreas)
- Oxalate nephropathy (build-up of calcium oxalate which may lead to kidney stones)
Xenical/Orlistat can also affect other medicines you are taking, such as anticoagulants. Always tell the doctor about all your medicines and read the patient information leaflet fully before you start taking Xenical or Orlistat.
What diet should I follow while taking Xenical or Orlistat?
Follow a balanced, calorie-controlled diet with no more than about 30% of calories from fat, spread across meals, and limit high-fat snacks between meals. PrivateDoc offers a diet guide developed with nutritionist Glen Matten.
Where to buy Xenical or Orlistat online?
Use a regulated UK service where a prescriber reviews your consultation and medicines are sourced appropriately. PrivateDoc uses UK-registered doctors and supplies genuine MHRA-regulated medicines.
What is the difference between Xenical and Orlistat?
Both contain 120mg orlistat. Xenical is the original branded medicine; generic orlistat is the non-branded version with the same active ingredient. Your prescriber can explain options for your treatment plan.
Can I exercise while taking Xenical or Orlistat?
Yes. Exercise alongside a healthy diet supports weight loss and long-term weight maintenance when you stop medication. Increase activity gradually according to your fitness level.
References
- A systematic review of the clinical effectiveness and cost effectiveness of Orlistat in the management of obesity – https://www.nice.org.uk/guidance/ta22/documents/orlistat-for-treatment-of-obesity-in-adults-hta-report2
- https://www.medicines.org.uk/emc/files/pil.2592.pdf
- https://www.medicines.org.uk/emc/product/2592
- Side effect list compiled from data taken from www.medicines.org.uk – Please visit their website for a complete and comprehensive list. Medicines.org is a stand-alone entity and is in no way associated with this site.
The expert team leading our online clinics 2025
PrivateDoc is happy to introduce you to some of our leading UK licensed clinicians who will be supporting you through your weight loss journey
Dr Ruchira Karunadasa
Chief Medical DirectorDara O'Malley
Director of PharmacyCaroline Marshall
Head of OperationsQuality care when you need it most
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