Is Alli the solution to your weight-loss woes? A Mayo Clinic specialist discusses the effectiveness of Alli, an over-the-counter weight-loss pill.

By Mayo Clinic Staff

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

Here, Donald D. Hensrud, M.D., a preventive medicine and nutrition specialist at Mayo Clinic, Rochester, Minnesota, answers common questions about Alli.

Alli is the reduced-strength, 60-milligram version of orlistat (Xenical), a 120-milligram prescription drug.

Xenical is approved for use by people who have a body mass index (BMI) of 30 or more (obese), as well as people with a BMI of 27 to 29 (overweight) who have other health risk factors such as high blood pressure or diabetes.

Alli is approved for over-the-counter sale — with some exceptions — to overweight adults 18 years and older. 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.

In 2010, the Food and Drug Administration (FDA) published a safety review of orlistat 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

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. Alli inhibits the work of lipase. When you take the drug with a meal, about 30 percent of the fat you consume isn't broken down and is eliminated through bowel movements.

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.

In a 2014 review of clinical trials, researchers assessed the effect of weight-loss pills in studies that were at least one year long. People who ate a calorie-restricted diet, exercised regularly and took Alli lost an average of 5.5 pounds (2.5 kilograms) more in one year than did people who only dieted and exercised.

About half the 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.

One 60-milligram Alli pill is taken with a fat-containing meal up to three times a day. Daily fat intake should be distributed over the three main meals and should be no more than 30 percent of total calories. The manufacturer recommends a fat intake of about 15 grams a meal.

If you eat a meal that contains no fat, then you should not take a dose of Alli. If you take Alli with a high-fat meal, you will likely experience more-severe gastrointestinal side effects.

Alli can reduce the absorption of fat-soluble nutrients, including beta carotene and vitamins A, D, E and K. Take a multivitamin at bedtime and at least two hours after your last dose of Alli.

Gastrointestinal side effects are related to undigested fats passing through your digestive system. They generally subside over time and with appropriate use of the medication. These side effects include:

  • Abdominal pain or discomfort
  • Oily discharge from the anus
  • Gas with oily anal discharge
  • Oily stools
  • More-frequent bowel movements
  • Urgent or hard-to-control bowel movements

Other possible side effects include:

  • Headache
  • Back pain
  • Upper respiratory infection

Talk with your doctor before taking Alli about possible interactions with other medications, particularly if you take medications for any of the following conditions:

  • Diabetes
  • Thyroid disease
  • Irregular heartbeat
  • Cardiovascular disease
  • Seizures

You should not use Alli if you:

  • Are at a healthy weight
  • Have had an organ transplant
  • Are taking cyclosporine (Neoral, Sandimmune, others)
  • Have problems already absorbing food
  • Are pregnant or breast-feeding

A weight-loss plan with diet, exercise and drug therapy is generally considered successful if you lose about 1 pound (0.5 grams) a week during the first month and have lost 5 percent or more of the pre-treatment body weight within one year.

If the treatment is successful, you are more likely to keep weight off or lose more weight if you continue with the diet, exercise and drug treatment plan.

Most weight loss with the medication occurs within the first few months. If you have adhered to the diet and exercise plan and have not lost at least 5 percent of your initial body weight within a few months, continuing the medication may be of little benefit.

If you have not lost 5 percent of body weight within a year on the plan, discontinuing the drug would be a reasonable choice. The risks, side effects and cost associated with taking the medication would likely override any potential benefit.

Alli isn't an easy answer to weight loss and is meant only to supplement — not replace — a healthy diet and regular physical activity.

Work with your doctor to evaluate the potential benefits and risks of Alli or any other weight-loss drugs. As a team, you and your doctor can create the most effective weight-loss plan for you.

Feb. 07, 2015