Orlistat 120mg capsules can help people who are overweight to lose weight and prevent weight regain, reducing the risk of obesity related health conditions.
Orlistat is a prescription-only weight loss aid that contains the active ingredient orlistat. Orlistat works by preventing the absorption of dietary fat into the body. It is the generic version of the branded medication, Xenical. To get the best results, Orlistat should be taken in combination with a low calorie, low fat diet, and exercise.
Orlistat can also be taken after you have lost weight to stop you from putting weight back on.
1 month / 84 capsule(s) - £44.00
Orlistat is the brand name for the medication containing the active ingredient orlistat. Orlistat may be a suitable weight loss treatment if you are overweight with a body mass index (BMI) over 30. You can also be prescribed orlistat if your BMI is over 28 and you have a health condition that can be helped by weight loss. Orlistat isn’t an alternative to a healthy diet and regular physical activity.
Orlistat is a type of medication called a lipase inhibitor that works by blocking the enzyme that breaks down fat. This stops some of the dietary fat you eat from being absorbed into your body. This fat then leaves your body with other waste in your stools.
Orlistat comes in capsule form with each capsule containing 120mg of the active ingredient orlistat. You should take orlistat exactly as your doctor tells you to, and not change the dose.
- Take one orlistat capsule with water during a meal or up to one hour after you have finished eating.
- If you skip a meal, or if your meal does not contain any fat, you do not need to take orlistat.
- If you forget to take orlistat and it is within one hour of your last meal you should take your capsule as soon as you can.
- If it is more than one hour since your last meal, skip the dose and take your next capsule with your next meal as normal.
If you aren’t sure how to take orlistat correctly or have any questions about it, ask your doctor or pharmacist.
Dietary requirements while taking orlistat
You should avoid eating foods that contain over 30% fat and try to spread your daily amount of protein, carbohydrate, and fat evenly over three main meals.
Orlistat stops your body from absorbing some fat soluble vitamins and minerals, so you will need to take a multivitamin supplement containing vitamins A, E, D, K, and beta carotene once a day. Take these at least two hours before or two hours after taking orlistat. If you prefer, you can take your multivitamin before you go to bed.
Orlistat can sometimes cause side effects. Most of the side effects are not serious and go away on their own. Tell your doctor if you have any serious side effects or if the side effects get worse or do not get better.
Common side effects include:
- change in your bowel movements such as needing to poo more often, needing to go quickly, being unable to hold your poo, oil in your poo or on your underwear, diarrhoea (loose, runny, or frequent poo)
- flatulence (farting)
- abdominal pain
- pain in your rectum (bottom)
- irregular periods
- anxiety (feeling worried or nervous)
Serious side effects from taking orlistat are less common. Tell your doctor or healthcare provider immediately if you have:
- itchy, red bumps on the skin (hives)
- a rash
- difficulty breathing or swallowing
- severe stomach pain, especially in the top right side of your stomach
- nausea (feeling sick)
- vomiting (being sick)
- reduced appetite (not feeling hungry)
- yellowing of your skin or the whites of your eyes
- dark coloured urine (pee)
- light coloured stools (poo)
For a full list of side effects and contraindications please read the patient information leaflet.
Orlistat is not safe for everyone. Before prescribing orlistat your doctor will ask you some questions about your health, whether you have any allergies and if you are taking any other medications. Make sure you tell your doctor if you:
- are under 18 years of age
- are allergic to orlistat
- have or have ever had an eating disorder like anorexia nervosa or bulimia
- have diabetes
- have or have ever had kidney stones
- have or have ever had pancreatitis (inflammation of the pancreas)
- are pregnant or breastfeeding
- have ever had an organ transplant
- have cholestasis (a condition where bile from the liver to the small intestine is blocked)
- have malabsorption syndrome (a condition where your body does not absorb food properly)
Some other medications may affect how orlistat works and may not be suitable to take with orlistat. Make sure you tell your doctor about any other medications you are taking, including vitamins and herbal supplements especially:
- blood thinners (anticoagulants) like warfarin (Coumadin)
- diabetes medications like glipizide (Glucotrol), glyburide (DiaBeta, Dynase, Micronase), metformin (Glucophage), and insulin
- blood pressure and heart medications like amiodarone
- thyroid medications like levothyroxine
- any other weight loss medications
- medications to suppress your immune system (immunosuppressants) like cyclosporine (Neoral, Sandimmune)
If you are taking a contraceptive pill, orlistat might affect how well it works if it causes you to be sick (vomit) or have diarrhoea. If you vomit less than 3 hours after taking your contraceptive pill or you have diarrhoea for more than 24 hours you should use additional contraception (like condoms) and speak to your doctor for advice. You might need to change to a type of contraception that is not taken by mouth, like the contraceptive injection, implant or coil.
Orlistat is also available under the brand names Xenical and Alli. They all contain the same active ingredient, orlistat.
Xenical and orlistat contain 120mg of orlistat and Alli contains 60mg. Orlistat and Xenical block 1/3 of the fat you eat from being used by the body and Alli blocks ¼ of the fat from being absorbed. You can buy Alli over the counter, but you need a prescription from your doctor for orlistat and Xenical.
Liraglutide (Saxenda) is another medication that your doctor can prescribe to help you lose weight. Liraglutide is taken by injection once a day. It works by making you feel less hungry.
Various herbal supplements are available that claim to help with weight loss, but there is no scientific evidence that they work and many of them may cause serious side effects. Other options that can help you lose weight include diet and exercise alone or surgery such as bariatric surgery. Talk to your doctor about which option is right for you.
Is orlistat good for weight loss?
Studies have shown orlistat to be very effective when combined with a calorie controlled diet and exercise
How much weight did you lose with orlistat?
In the same study, people taking orlistat over a six month period lost an average of 4.65kg compared to 2.5kg when taking a placebo (sugar pill)
How quickly does orlistat work?
Most people taking orlistat lose around 5% of their body weight within three months. If you haven’t lost this amount of weight in the first three months, your doctor will probably stop prescribing orlistat.
How long does orlistat work for?
Orlistat works for as long as you are taking it. If orlistat is working well for you, your doctor can continue to prescribe it for as long as you need it.
Is orlistat addictive?
Although orlistat itself is not addictive, some people may become addicted to losing weight and may abuse orlistat in order to lose an unhealthy amount of weight
How long should I continue taking orlistat?
You should continue taking orlistat for as long as your doctor tells you to.
Dr Kathryn Basford
Dr Kathryn Basford is a qualified GP who works as a GP in London, as well as with ZAVA. She graduated from the University of Manchester and completed her GP training through Whipps Cross Hospital in London.Meet our doctors
Article created: 06 Jan 2022
Last reviewed: 06 Jan 2022
MedlinePlus. Drug info. Orlistat 15th January 2016 Accessed 5th January 2022
WebMD. Orlistat capsules: Uses,side effects, and more Accessed 5th January 2022
NHS: Conditions. Obesity treatments 16th May 2019 Accessed 5th January 2022
Patient info: Orlistat 1st March 2018 Accessed 5th January 2022
NCBI: Evaluation of efficacy and safety of orlistat in obese patients April-June 2011 Accessed 5th January 2022