How to get the best results from orlistat

Orlistat is a medicine to help with weight loss. You take it alongside lifestyle changes including a healthy diet and exercise. You can buy orlistat as the generic version or as Xenical, the branded version.

If you have a high BMI, your doctor or pharmacist may have recommended you take orlistat to help you lose weight.

You can take orlistat if your BMI is:

• 30 or above
• 28 or above and you have certain conditions, such as type 2 diabetes or high blood pressure

Orlistat helps reduce the amount of fat your body absorbs from food. Normally, enzymes called lipases in your digestive system break down fats so your body can absorb them. Orlistat blocks these enzymes, which prevents some of the fat in your food from being absorbed.

Orlistat reduces the amount of fat you absorb from the food you eat by about 30%. Instead of absorbing these fats, your body will pass them out when you go to the toilet.

One study found that patients taking orlistat lost significantly more weight than those on a placebo, with many continuing to lose weight for up to a year. Other research has demonstrated that orlistat not only aids in weight loss but also helps in preventing weight regain over long term periods.

To get the best results from orlistat, combine it with a healthy diet and regular physical activity.

Eat a healthy, balanced diet

Making simple dietary changes can help you get the best results from orlistat and improve your overall health:

• eat a healthy, balanced diet every day
• limit your fat intake to no more than 30% of your daily calories
• spread your intake of fat, carbohydrates, and protein across three meals a day
• include plenty of fruits and vegetables and limit foods that are high in fat
• consider taking a vitamin supplement that includes vitamins A, D, E, and K, because orlistat can reduce the absorption of fat-soluble vitamins

Avoid foods with high fat content

When taking orlistat, eating meals that are very high in fat can increase the risk of side effects, such as stomach pain, diarrhoea, wind, oily discharge or fatty stools. Reducing your daily fat intake can help minimise these side effects and make the medication more effective.

Use nutrition labels to check fat content and try to limit foods with more than 5g of fat per 100g. Very high fat foods include butter, cheese, fried foods, fatty meats, chocolate and cakes.

You can swap high-fat foods for lower-fat alternatives to reduce side effects, for example:

• butter → low-fat spread
• full-fat milk → skimmed or semi-skimmed milk
• cheese → cottage cheese
• chips/roast potatoes → mashed or boiled potatoes
• chocolate, sweets, cakes → crispbreads or rice cakes

➤ The NHS also offers a free food scanner app to help you choose healthier options.

Get plenty of exercise

Orlistat works best when you increase the amount of exercise you do. Research shows that people lose more body fat and improve their fitness when they combine orlistat with regular aerobic exercise than with diet and medication alone.

Even moderate exercise – such as brisk walking, hiking or riding a bike – helps maximise weight loss and improve overall health. Regular activity also supports maintenance of long‑term results once you stop taking orlistat.

Follow the dosage guidelines

Make sure you are taking the right dose of orlistat. Take 1 capsule 3 times a day with a drink of water, ideally just before, during, or no later than 1 hour after eating a meal. If you skip a meal or have a meal that does not contain any fat, you should not take a dose of orlistat.

Orlistat works by blocking the absorption of some of the fat from your meals, so each dose should be taken with a meal that contains a small to moderate amount of fat – around 30% of your caloric intake should come from fat. However, it’s important to avoid meals that are too high in fat, as consuming excessive amounts can lead to uncomfortable side effects, such as stomach discomfort and oily stools.

Monitor your progress

Tracking your measurements can help you assess how effectively orlistat is working.

✓ Changes in waist circumference are a meaningful way to gauge fat loss, particularly abdominal fat, which orlistat has been shown to reduce.

✓ Taking measurements of areas such as your waist and thighs can also provide a clear picture of your progress.

✓ Weighing yourself once a week will also help with progress tracking.

“Orlistat works best when it’s used alongside healthy lifestyle changes. Regular physical activity and a balanced, nutritious diet not only support weight loss but also help people get the most consistent results from treatment.” - Dr Crystal Wyllie, Online Doctor.

People often experience similar patterns of progress with orlistat, but everyone’s experience is unique. Your rate of weight loss, the timing of side effects, and how your measurements change may differ from other people.

The first week

Most people see little or no significant weight loss in the first week. Some may notice a small drop related to water weight or very modest fat loss, but meaningful results typically take longer.

It’s common to experience gastrointestinal effects such as oily stools, flatulence, or urgent bowel movements – especially if your meals contain higher amounts of fat. These side effects are expected and usually mild, improving as you adjust your diet.

Early results are subtle. During this week, focus on building routine, consistency, and healthy eating habits.

The first month

In the first month, a loss of around 1 to 3kg is typical when diet and activity changes are in place, although results vary.

Even if you are not yet losing significant amounts of weight, you may start to notice small reductions around the waist. This is a meaningful sign of progressing fat loss.

Gastrointestinal symptoms often peak within the first 2 to 4 weeks and usually improve as your body adapts and you reduce dietary fat.

The first year

Research shows that people typically lose at least 5 to 10% of their starting body weight over 12 months when orlistat is used alongside diet and exercise. Many people notice their waist measurement reduces over the year. This is linked with improvements in health markers such as blood sugar and cholesterol levels.

It’s normal for weight loss to slow after 3 to 6 months. Maintaining habits and making small adjustments – like increasing activity or reducing calorie intake – can help overcome plateaus.

Regular check-ins with your doctor can help assess progress and adjust your plan if needed. Self-monitoring of weight and measurements keeps you engaged and aware of your progress.

Mysimba

Mysimba contains the active ingredients naltrexone and bupropion. The treatment targets the part of your brain that controls your appetite, in turn helping to suppress your appetite.

How you take Mysimba changes gradually over weeks. From week 1 you take 1 tablet once a day in the morning, from week 2 you should take 2, and so on. You can find out more specific information on our dedicated page. The maximum recommended dose of Mysimba is 2 tablets twice a day after week 1.

Weight loss injections

If you are uncertain whether oral weight loss treatment is right for you, there are effective weight loss injection alternatives available.

Wegovy

Wegovy is a GLP-1 treatment available also in the injection form as well as the tablet form. Like the Wegovy tablet, the Wegovy injection contains semaglutide. Similar to the tablet, you start on a lower dose when starting Wegovy (0.5mg) and titrate up to a maximum dose, monitored by a doctor.

Wegovy injection works in the same way as the Wegovy tablet to reduce your appetite and increase fullness, this is because they contain the same active ingredient. However, note that because of the different ways they are administered, you may experience different effects.

➣ Find out more about Wegovy injection.

Mounjaro

Mounjaro is a GLP-1 medication that is injected once-weekly. It contains tirzepatide which works to increase your feeling of fullness by slowing down the emptying of your stomach after a meal; this can lower your appetite, which can help you lose weight. When taking Mounjaro you are monitored by a doctor as you start on the dose of 2.5mg, and can titrate up to a maximum dose of 15mg.

➣ Find out more about Mounjaro.