How Does Orlistat Work & What Makes It Effective?

Orlistat is one of the most popular weight loss treatments available. But what exactly makes Orlistat so popular, and how does it actually work?

Updated: Wednesday 06 July 2022

Cheerful couple enjoying healthy food and orange juice in a cosy home

The enzymes in your stomach and small intestine, gastric and pancreatic lipases, break down the fats from foods into fatty acids and glycerol so they can be more easily absorbed into your bloodstream. These molecules are then distributed throughout the body to be stored as reserves so they can supply your body with energy when required. An increased intake of energy from food and doing less exercise usually leads to an excess supply of fats that are not getting used up, which can lead to weight gain.

What is Orlistat and what is it used for?

Orlistat is one of the most popular weight loss treatments and contains 120mg of the active ingredient orlistat. This treatment is recommended for adults with a BMI of 30 or 28 when in conjunction with additional risk factors such as heart disease, high blood pressure, high cholesterol and type 2 diabetes.

How does Orlistat work?

Orlistat works to increase weight loss by affecting the enzymes inside the digestive system. Orlistat binds to the gastric and pancreatic lipase enzymes in the stomach and small intestine so they cannot bind to fat molecules and break them down. Furthermore, the undigested fat that has not been absorbed is passed out through the stool. This reduction in fat levels means the remaining stored fatty acids and glycerol can be used up by the body for energy.

Overall, Orlistat only blocks around 1/3 of the fat from a meal from being absorbed, so it is recommended to look at lifestyle changes that can be made to increase the effectiveness of the Orlistat capsules.

How Orlistat Works

How do you take Orlistat?

One Orlistat capsule should be swallowed with water 3 times a day with each of your meals containing fat. It should be taken either 1 hour before, during, or 1 hour after the meal. For it to work effectively, it should be taken over the span of 12 weeks, where it will aim to shed 5% of the body weight. However, the true effectiveness of Orlistat will depend on individual circumstances and lifestyle choices.

Orlistat is only effective in the presence of dietary fat, meaning if your meal does not contain fat, or you miss eating it, there is no need for you to take a dose of Orlistat, so you can skip that dose.

It is also recommended that you stick to a balanced diet; one rich in fruit and vegetables and you ensure that your daily intake of protein, carbohydrate and fat is distributed equally over your 3 main meals. Learn more about the diet habits recommended for people taking Orlistat in our essential guide.

How effective is Orlistat at helping you lose weight?

Orlistat is a clinically proven weight loss medication, which has been shown to help patients lose up to 50% more weight compared to those that were just solely diet [1] . Research has demonstrated that an increase in faecal fat can be seen as early as 24 to 48 hours after taking a dose [2].

The best way to ensure Orlistat works effectively is to make necessary changes to your lifestyle and environment, and uphold your commitment to the process and stay motivated. These possible lifestyle changes can include:

  • Increasing daily exercise
  • Reducing alcohol consumption
  • Stopping smoking
  • Moderating calorie intake

What are the side effects of Orlistat?

All medications can potentially cause side effects, but this does not mean you will experience them. As Orlistat works by passing fat through your faeces, the most common side effects include:

  • Abdominal discomfort
  • Oily spotting
  • Faecal urgency
  • Flatulence
  • Fatty/oily stools and increased defecation

What other weight loss treatments are available?

The active ingredient orlistat, found in Orlistat medication, is also in several other weight loss medications. Xenical is the branded version of Orlistat, so both contain 120mg of orlistat. Alli and Orlos are other branded weight loss medications, but they contain a lower dose of orlistat at 60mg, so are usually recommended for people with a BMI of 28 or above.

Orlistat is an effective method of losing weight, but ensure that whilst you are taking the tablets you are keeping a realistic mentality towards your weight loss journey, staying motivated, and understand that Orlistat is not a sole treatment to losing weight, just an aid. It will only continue working effectively if you make lifestyle and dieting changes in conjunction with taking Orlistat doses.

Amber Mitchell-Hanna

Written by: Amber Mitchell-Hanna

Pharmica Medical Writer

Amber is an experienced writer and content specialist, graduating from De Montfort University with an LLB & an MA in Investigative Journalism.

She particularly enjoys creating informative health content, debunking medical misconceptions, and championing inclusion and diversity.

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