Dr Clare Morrison

Article by Dr Clare Morrison

How Does Alli Work?

Alli (Orlistat 60 mg) is used to treat obesity, and works by absorbing the fat from the food you eat. Lipase, an enzyme found in the digestive tract, assists in breaking dietary fat down into smaller components so it can be stored for energy. Alli stops this working, prohibiting about a quarter of the fat in meals from being absorbed. It’s important to commit to a low-fat diet to manage the effects of Alli. If you do so, the action of the capsules will help your efforts by assisting you to lose more weight. For every 2 kg you lose from dieting, Alli can help you lose 1 kg more!

How long do I need to take Alli?

In general, most weight loss, as long as you’ve followed a balanced diet, occurs in the first few months. If you haven’t lost at least five percent of your initial body weight within this time, continuing the medication could be of little benefit (the side effects and cost linked to the medication would probably override any potential benefit).

How to take Alli

Step 1: Take Alli three times a day at mealtimes, before, during or up to an hour after each meal

Step 2: Swallow the capsules whole with water

Step 3: Do not take more than three capsules per day

Step 4: Avoid taking Alli if you’re going to eat a meal that doesn’t contain fat, or if you miss a meal

Step 5: Remember to take a multivitamin every day before bed to ensure you absorb vitamins A,D, E and K

Side effects of Alli

The most common side effects of Alli (Orlistat 60mg) include:

  • An oily rectal discharge
  • Passing gas with an oily discharge
  • Urgent need to empty bowels
  • Oily or fatty stools
  • An increase in the amount of bowel movements
  • An inability to control bowel movements

When you decide to lose weight with Alli, it’s important to know which treatment is the most effective. For example, Alli contains less Orlistat than Xenical, and so noticeable weight loss results with Alli could take longer. What’s right for one person, isn’t always right for another – so it’s vital you consult with a doctor or pharmacist to discover more about what works for you.

Alli diet plan

Finally, it’s important to remember that Alli isn’t a miracle weight loss drug, so order to stay healthy and lose weight, it’s important to eat the right diet. So how does Alli work best? One thing you can do is to make your diet nutritionally balanced, ensure that 30 percent of the calories you consume come from fat. The best diet will be rich in fruit and vegetables and three main meals a day will ensure you can maintain a balanced diet of the proteins, fats and carbohydrates your body needs.


For more information about how Alli works, contact one of our customer service team.


Dr Clare Morrison
Dr Clare Morrison
Experienced General Practitioner in Hampshire since 1995, with particular interest in Nutrition, Obesity and Smoking Cessation.
Originally published July 03 2017, updated July 05 2019