Orlistat Capsules

Orlistat is the generic version of Xenical and the active ingredient in the medication. It’s a form of medicated weight loss that works by stopping the absorption of digested fat and reduce the calories consumed from the fat in the food and helps with weight loss. It is taken by mouth, like tablets and can be taken up to three times a day. When paired with a diet and lifestyle change, it can help people achieve meaningful weight loss. 

Orlistat is a prescription-only weight loss medication used to help with weight loss and maintenance, in combination with a balanced diet and physical activity. It can be prescribed to those with a BMI over 30 kg/ m² (obesity) or those with a BMI of 28 kg/ m² with a weight-related health condition. 

At The Family Chemist, we always consider your BMI and medical history to determine treatment eligibility and safety.

Orlistat, acts on certain enzymes in the gut to stop the breakdown and absorption of fat that has been consumed during a meal. This way the calories absorbed from the food are lower and the fat is also not stored in the body, leading to eventual weight loss.  

Orlistat pill is known to block around one third of the fat from food eaten from being absorbed. Any fat that isn’t digested is then passed through your stools.

No. Orlistat works to stop the absorption of fat from the main meals but it cannot break down existing fat in the body as it only works on the enzymes involved in digestion of fat.

Take one 120mg Orlistat capsule with water, immediately before, during or up to 1 hour after each main meal.  

Don’t chew or break the capsule and swallow it whole. 

Eat a nutritionally balanced diet; ensuring that your meal doesn’t have more than 30% of its calories from fat. This will support weight loss and lower the chances of side effects from Orlistat.  

If you miss a meal, or your meal contains no fat, just skip the Orlistat pill with that meal.

In trials, Orlistat has helped people achieve weight loss when it’s combined with a reduced-calorie diet and physical exercise. About 35-55% of people lost at least 5% of their starting body weight, and around 16-25% lost 10% or more of their weight. Orlistat can help you by supporting a steady, gradual weight loss. 

You should aim to lose 5% of your starting weight by week 12, however, the speed and quality of Orlistat’s side effects depend on your diet and lifestyle.

Orlistat, like any other medication, can cause some side effects. Some of the very common (may affect more than 1 in 10 people) side effects are: 

• Abdominal pain or discomfort 

• Oily spotting or discharge from the back passage or fatty stools 

• More frequent, or urgent bowel movements 

• Headaches  

The list above does not include all possible side effects, therefore it is vital that if you experience any serious side effects whilst using this medication to consult a healthcare professional and if you experience side effects not listed above, complete a MHRA Yellow Card report. 

Be sure to read through the patient information leaflet before taking any new medication to familiarise yourself with the possible side effects, cautions, and contraindications. You should only take Orlistat capsules once you have understood all the warnings and precautions. If you are concerned discuss this with your doctor or a The Family Chemist clinician.

If you miss a dose of your Orlistat capsule, take it as soon as you remember if it’s been less than an hour since your last main meal. After that, you can continue taking it as normal. 

Do not double up the number of capsules to make up for a missed dose, as this only increases the likelihood of having side effects.

Xenical is a branded version of the medication Orlistat. There is no difference between the two medications other than the brand.  

If you wish to switch between the two, you can stay on the same dose. 

It’s important to talk to your GP or prescriber if you’re wishing to switch your weight loss medication.

There are a range of alternative medications to Xenical that are licensed for use in the UK. These include weight loss injections, and weight loss tablets, which are available through The Family Chemist. All treatment options are provided alongside dietary and lifestyle changes.

If medicated options are not suitable for you, there are some alternative options to consider: 

1. Behavioural Therapy: Weight management often involves changes in diet and exercise habits. Behavioural therapy, either individually or in group settings, can provide valuable strategies and support for making lifestyle changes. 
2. Dietary Counseling: Working with a registered dietitian or nutritionist can help you develop a personalized meal plan that aligns with your weight loss goals and dietary preferences. 
3. Exercise Programs: Regular physical activity is essential for weight management. Consider engaging in an exercise program or working with a personal trainer to establish a fitness routine. 
4. Lifestyle Changes: Small but sustainable changes in your daily habits, such as portion control, mindful eating, and adequate sleep, can contribute significantly to weight loss. 
5. Surgical Options: In cases of severe obesity, surgical procedures like gastric bypass, gastric sleeve, or lap band surgery may be considered a last resort. 

When taking Xenical capsules, it’s important to reduce the amount of processed, greasy or fatty food. This includes fatty means, deep-fried food, crisps and pastries.  

This will help reduce the chances of you experiencing side effects while taking Xenical.

Orlistat can stay in your system for up to 5 days after the last dose. However, this may vary depending on each person, their diet and how long they had been taking Orlistat for. If you’re experiencing side effects after 5 days, please speak with your GP or clinician.

Orlistat works to reduce the absorption of fat from the diet and as a result, can lower the amount of fat-soluble nutrients (such as vitamin D, E and beta-carotene) being absorbed. As with many other medications, it may interfere with other medications or make them less effective. It’s important to let us know your full medical history so that our clinicians can ensure Orlistat is the best choice for you. 

To ensure you still have sufficient amount of nutrients, follow a well-balanced diet with considerable amounts of fruit and vegetables. Your doctor may suggest taking multivitamin supplements.

Orlistat can reduce the absorption of contraceptive pills (e.g. mini pill or combined pill). If you experience severe diarrhoea or vomiting, you should use additional barrier methods or other forms of contraception during the time you’re experiencing these side effects and for up to 7 days after.

Orlistat safety update (2024) Medicines and Healthcare product Regulatory Agency [accessed 20th February 2026] 

Xenical emc [accessed 20th February 2026] 

Overweight and obesity management (2025) NICE guidelines NG246 [accessed 20th February 2026]