Orlistat

Orlistat is a drug used to help people lose weight. It is available by prescription (sold as Xenical) and without a prescription (sold as Alli). The medication is taken with each fat-containing meal, up to three times daily. It works by inhibiting the action of enzymes that break down fat, which reduces fat absorption in the body. Side effects of orlistat include stomach pain, gas, and oily spotting.

What Is Orlistat?

Orlistat (Alli™, Xenical®) is a weight loss medication. It is available with a prescription (sold under the name Xenical) or without a prescription (sold under the name Alli).
 
(Click What Is Orlistat Used For? for more information, including possible off-label uses.)
 

Who Makes It?

The prescription version of orlistat (Xenical) is made by Roche Pharmaceuticals, while the non-prescription version (Alli) is made by GlaxoSmithKline Consumer Healthcare.
 

How Does Orlistat Work?

Orlistat works by decreasing the absorption of fat from your diet. The stomach and intestine have enzymes, called lipases, that break down fat into smaller molecules, which are then absorbed from your digestive tract. Orlistat binds to lipases and inhibits their activity, helping to decrease fat absorption. However, the drug does not have any effect on carbohydrates or protein.
 

When and How to Take It

General considerations for when and how to take orlistat include the following:
 
  • The medication comes in capsule form. It is taken by mouth with each fat-containing meal, up to three times per day.
     
  • If you miss a meal, or if you have a meal without any fat, you should skip the dose of orlistat.
     
  • Orlistat should be combined with a reduced-calorie, low-fat diet. Eating too much fat increases the risk of side effects. In general, you should try to limit your fat intake to less than 30 percent of your total daily calories.
     
  • For the medication to work properly, it must be taken as prescribed.
     

Dosage Information

There is only one recommended orlistat dose, regardless of your age, weight, or other medications or medical conditions. However, the dosage for the prescription version is not the same as that for the non-prescription version.
 
(Click Orlistat Dosing for more information.)
 

Side Effects of Orlistat

As with any medicine, side effects are possible with orlistat. However, not everyone who takes the drug will experience side effects. In fact, most people tolerate it quite well. If side effects do occur, in most cases, they are minor and either require no treatment or can easily be treated by you or your healthcare provider. Serious side effects are less common.
 
Common side effects include but are not limited to:
 
  • Oily spotting (uncontrolled anal seepage of oil)
  • Abdominal pain (stomach pain)
  • Urgent need to have a bowel movement
  • Gas with discharge of oil or stool.
     
(Click Orlistat Side Effects to learn more, including potentially serious side effects you should report immediately to your healthcare provider.)
 

Drug Interactions

Orlistat can interact with a number of other medications (see Drug Interactions With Orlistat).
 

What Should I Tell My Healthcare Provider Before Taking Orlistat?

Talk with your healthcare provider prior to taking the drug if you have:
 
  • Diabetes
  • A thyroid disorder
  • Had an organ transplant
  • A medical problem that decreases your ability to absorb food
  • Gallbladder problems
  • A history of kidney stones
  • Had pancreatitis.
     
Also, let your healthcare provider know if you are:
 
Make sure to tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.
 
(Click Precautions and Warnings With Orlistat to learn more, including information on who should not take the drug.)
 

What If I Take an Overdose?

It is not known what exactly to expect from an orlistat overdose, other than the usual side effects (which might occur more severely). If you happen to take too much, seek immediate medical attention.
 
(Click Alli Overdose or Xenical Overdose for more information.)
 

How Should It Be Stored?

Orlistat should be stored at room temperature, away from moisture and heat. Keep the capsules in an airtight container. Keep this and all other medications out of the reach of children.
 

What Should I Do If I Miss a Dose?

If you do not take your orlistat as scheduled, take the missed dose, if it is within one hour of the meal during which you missed the dose. If it is an hour or more later, skip the missed dose and continue with your regular schedule. Do not take a double dose.
 

Available Strengths

Orlistat capsules come in the following strengths:
 
  • Orlistat 60 mg (Alli, the non-prescription version)
  • Orlistat 120 mg (Xenical, the prescription version).
     

Is There a Generic Version of Orlistat?

Currently, no generic versions of orlistat are licensed for sale (see Generic Alli or Generic Xenical).
 
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