W8MD weight lossOrlistat (Xenical)

Available in lower dose without prescription (Alli) Approved for adults and children ages 12 and older

Mechanism of action of Xenical

Works in your gut to reduce the amount of fat your body absorbs from the food you eat

Why is this medication prescribed?

Orlistat is used is a weight loss medication, both OTC (ALLI) and prescription strength called Xenical.

Can orlistat be used to help maintain weight?

Yes. Orlistat is also used after weight-loss to help people keep from gaining back that weight.

How does Orlistat work for weight loss?

Orlistat is in a class of medications called lipase inhibitors which work by preventing some of the fat in foods eaten from being absorbed in the intestines which is then removed from the body in the stool.

How should this medicine be used?

Orlistat comes as a capsule and a nonprescription capsule to take by mouth.

How often should one take Orlistat?

  • It is usually taken three times a day with each main meal that contains fat.
  • Take orlistat during a meal or up to 1 hour after a meal.
  • If a meal is missed or does not have fat, you may skip your dose.

What special dietary instructions should I follow?

Follow the diet program your doctor has given you, which usually is a low fat diet in most cases.

What foods to avoid while taking Orlistat?

While you are taking orlistat, you should avoid foods that have more than 30% fat.

What vitamins may not be absorbed properly with Orlistat?

Orlistat blocks your body’s absorption of some fat-soluble vitamins and beta carotene, and hence when you use orlistat you should take a daily multivitamin that contains vitamins A, D, E, K, and beta-carotene.

What should I do if I forget a dose?

Take the missed dose only if it is within one hour of having a meal.

Weight lossWhat side effects can this medication cause?

  • oily spotting on underwear or on clothing
  • gas with oily spotting
  • urgent need to have a bowel movement
  • loose stools
  • oily or fatty stools
  • increased number of bowel movements
  • difficulty controlling bowel movements
  • pain or discomfort in the rectum (bottom)
  • stomach pain
  • irregular menstrual periods
  • headache
  • anxiety

Rare but more serious side effects:

  • hives
  • rash
  • itching
  • difficulty breathing or swallowing
  • severe or continuous stomach pain
  • excessive tiredness or weakness
  • nausea
  • vomiting
  • loss of appetite
  • pain in the upper right part of the stomach
  • yellowing of the skin or eyes
  • dark-colored urine
  • light-colored stools

Brand names

  • Alli®
  • Xenical®