Before taking Xenical, warnings and precautions for the drug should be reviewed with your healthcare provider. This includes telling him or her if you have a history of diabetes, thyroid disorders, or gallbladder problems. You should also be aware of side effects and how they may be avoided. Xenical warnings and precautions also apply to people who have certain allergies and women who are pregnant or breastfeeding.

• Had an organ transplant
• Diabetes
• A thyroid disorder
• A medical problem that decreases your ability to absorb food
• Gallbladder problems
• An eating disorder, such as anorexia nervosa or bulimia
• Had kidney stones
• Had pancreatitis.
   

• Pregnant or thinking of becoming pregnant
• Breastfeeding.
   

• Your healthcare provider should make sure that your excess weight is not caused by a medical problem (such as an underactive thyroid) before you take Xenical.
   
• Xenical can cause bothersome (and sometimes painful and embarrassing) intestinal-related side effects. In order to avoid these Xenical side effects, you should not eat too much fat while taking the drug. If you experience these side effects, try reducing your fat intake.
   
• You should take a multivitamin while you are taking Xenical, as the drug can lead to certain vitamin deficiencies.
   
• Xenical can interact with a number of different medications (see Xenical Drug Interactions).
   
• If you have diabetes or thyroid problems, make sure your healthcare provider is aware of your weight loss plans with Xenical. As you lose weight, your healthcare provider may need to adjust your dose of diabetes medications or thyroid medications.
   
• The medication could cause or worsen gallbladder problems, kidney stones, or pancreatitis. If you have these conditions (or have had them in the past), talk with your healthcare provider before taking Xenical. Let your healthcare provider know if you experience severe, constant abdominal pain, which may be a sign of these problems.
   
• Xenical may be misused by people with a history of eating disorders. Make sure to tell your healthcare provider if you have had an eating disorder in the past.
   
• Xenical is considered a pregnancy Category B medication. This means that it is probably safe for use during pregnancy, although the full risks are not known (see Xenical and Pregnancy).
   
• It is not known if Xenical passes through breast milk. Therefore, if you are breastfeeding or plan to start, discuss this with your healthcare provider prior to taking the drug (see Xenical and Breastfeeding).