Orlistat

Orlistat: How it works and important information.

In the stomach and small intestine, you’ll find enzymes, a catalyst that causes a particular biochemical reaction to happen. One such enzyme is called lipase. One of its jobs is to take the fat found in food and help store it as energy. Orlistat works by preventing the lipase enzyme from fulfilling this job. This means certain fats don’t get stored, but are instead excreted when you go to the toilet.

Orlistat, Alli and Xenical are sometimes referred to as ‘fat binders’, but this isn’t a technically accurate way of describing how they work. Instead of binding to fat itself, the active ingredient orlistat attaches itself to the enzymes that are responsible for breaking fats down. This stops them from being absorbed by the digestive system. This undigested fat is then passed out during a bowel movement. By absorbing less dietary fat, you can improve your body mass index (BMI) and reach your healthier target weight.

Orlistat can only be prescribed if you have a BMI of 30 or above or 28 or above and a weight-related condition like type 2 diabetes or high blood pressure.

Orlistat capsules are intended to be used alongside a calorie controlled diet that’s low on fat as part of a plan to help you lose weight safely and effectively.

Too much fat in your diet while taking Orlistat can increase the risk of side effects like an upset stomach, nausea, vomiting, bloating or changes in your bowel habits. This is because Orlistat prevents fat absorption, leaving the excess fat hanging around in your digestive system and leading to unwanted side effects.^[1]

So focus on limiting the amount of fat to maximum 30% of your daily calorie intake and avoid high fat foods like fried foods, full fat cheese and some take away meals. It’s also useful to check the ‘total fat’ per 100g column when reading food labels and choose foods with less than 5g fat per 100g.

Exercising regularly is also important to make sure you get the best results from your treatment. Typically, it’s recommended that you aim for 150 minutes of exercise weekly, split over three to five sessions, when you start the treatment. If you feel comfortable, you can increase the sessions’ duration and frequency gradually.

Unlike other appetite suppressing weight loss treatments like Wegovy and Ozempic, the capsules don’t affect the amount you want to eat, but instead prevent the fat found in foods you eat from being absorbed. Eating too much fat in your diet can contribute to being overweight.^[2]

Does Orlistat work?

Most studies say that Orlistat capsules are a safe and effective weight loss medication if they’re taken as part of a plan that includes dieting and regular exercise.

Compared to placebos, there’s evidence that Orlistat is very effective and well tolerated. ^[7]
In some clinical trials, it has been shown to help reduce body weight by 10% within six months.^[3] In one 54-week double-blind study of 539 obese adolescents in the United States and Canada, Orlistat was shown to significantly improve weight management.^[7]

Losing weight is a personal journey, and there is no one-size-fits-all approach to reaching your target. Orlistat capsules are designed to work alongside other healthy choices, such as eating a low fat diet and getting more exercise. Whereas other weight loss regimes are built entirely around reducing the amount of calories you consume, Orlistat capsules instead help you lose weight by controlling your dietary fat absorption. The capsules alter your body’s fat absorption — by absorbing less fat from the meals you eat, you can improve your overall body weight, which has been linked to lower risks of serious illnesses like chronic kidney disease^[4]
and diabetes.^[5]

How long before I lose weight on Orlistat?

If you take Orlistat capsules as part of a weight loss plan that includes a low fat diet and plenty of exercise, you may find that you lose up to 10% of your weight over six months. But the fact is, everyone is different, so there are no guarantees that it will happen in this timeframe.

If you haven’t noticed any changes in weight after several months of using it, alongside making changes to your diet and getting exercise, speak to your clinician about alternative treatments.

How to take Orlistat

Orlistat capsules are taken three times a day with a meal. You can take them just before, during or up to an hour after you eat. Swallow each capsule whole with water.

If you skip a meal, skip the tablet you’d have taken alongside it. For Orlistat to work, your meal needs to contain some level of fat. If you eat something without any fat content, you can skip that particular pill.

What if I forget to take one of my weight loss pills?

If you miss a dose and it’s been less than an hour since you’ve eaten a meal with fat in it, you can still take one of your capsules.

Don’t take Orlistat if you miss a meal, or your meal doesn’t contain any fat.

If it’s been more than an hour since your last meal, skip that particular dose and carry on taking the capsules as you normally would.

Do not take two capsules to make up for a missed one as this increases the risk of side effects and can pose a significant risk to your health.

Who can take Orlistat?

To start using Orlistat, you need to have a BMI of 30 or above (or 28 or above and an underlying health condition like type 2 diabetes or high blood pressure) that could benefit from weight loss. It will also usually only be prescribed if you’ve made significant effort to lose weight in the past.

BMI is a relatively simple formula used to calculate a person’s weight. It divides your weight in kilograms by your height in metres squared. A healthy BMI for an adult is anywhere between 18.5 to 24.9.

• Below 18.5 – underweight.
• Between 18.5 to 24.9 – healthy weight.
• Between 25 and 29.9 – overweight.
• Between 30 and 39.9 – obese.

It should be noted that body mass index (BMI) is not a perfect measure of your weight. For example, its ranges can change slightly for people with particular ethnicities because they may be more at risk from having a lower BMI. Other factors, like muscle mass, can also play a part. Athletes, such as boxers or weight trainers, may have a BMI that would usually be classed as obese despite them being a healthy weight for their particular activity level.^[1]

Orlistat can be prescribed ‘off-label’ for some people whose BMI is below 30 (or 28 with an underlying health condition).

You can’t take Orlistat if you suffer from certain conditions, like chronic malabsorption syndrome, cholestasis or if you’re breast-feeding. Orlistat should be taken as part of a weight loss plan that includes regular exercise and a calorie deficit diet.