Alli weight-loss pill: Does it work?

Is Alli — an over-the-counter weight-loss pill — the solution to your weight-loss woes?

By Mayo Clinic Staff

Alli (pronounced AL-eye) is an over-the-counter drug meant for overweight adults struggling to shed excess pounds. With its easy access and weight-loss promises, is Alli your answer for losing weight?

What is Alli?

Alli is a 60-milligram, over-the-counter version of orlistat (Xenical), a 120-milligram prescription drug. Both Alli and Xenical are meant to be used as part of a weight-loss plan that includes a low-calorie, low-fat diet and regular physical activity.

Alli is approved for use in adults 18 and older who have a body mass index (BMI) of 25 or more. Xenical is approved for use in adults with a BMI of 30 or more (obese), and those with a BMI of 27 to 29 (overweight) who have other health risk factors such as high blood pressure or diabetes.

Are there concerns about orlistat?

The Food and Drug Administration (FDA) published a safety review of orlistat in 2010 because of rare reports of serious liver injury in people using it. The FDA found no evidence to confirm that orlistat was the cause of the reported liver injuries.

However, Alli and Xenical labels were revised because of the reports. Talk to your doctor immediately if you have signs or symptoms that may indicate liver injury:

  • Itching
  • Loss of appetite
  • Yellow eyes or skin
  • Light-colored stool
  • Brown urine

How does Alli work?

Orlistat (the active ingredient in Alli) promotes weight loss by decreasing the amount of dietary fat absorbed in your intestines.

Lipase, an enzyme found in the digestive tract, helps break down dietary fat into smaller components, so it can be used or stored for energy. Orlistat inhibits the work of lipase. When you take the drug with a meal, about 25 percent of the fat you consume isn't broken down and is eliminated through bowel movements.

How much weight could I lose using Alli?

Alli may help you lose weight, but the weight loss will likely be modest — perhaps just a few pounds more than you would lose with diet and exercise alone.

More than 40 percent of people taking Alli while following a calorie-restricted diet and increasing physical activity lost 5 percent or more of their body weight within a year. Clinically meaningful weight loss — enough weight loss to begin lowering the risk of cardiovascular disease, diabetes and other diseases — is generally defined as 5 percent or more of body weight.

People who ate a calorie-restricted diet, exercised regularly and took Alli lost an average of 5.7 pounds (2.6 kilograms) more in one year than did people who only dieted and exercised.

Feb. 06, 2018 See more In-depth