The information provided here is meant to give you a general idea about each of the medications listed below. Only the most general side effects are included, so ask your doctor if you need to take any special precautions. Use each of these medications as recommended by your doctor, or according to the instructions provided. If you have further questions about usage or side effects, contact your doctor.

Medications for obesity should not be used alone. Rather, they should be part of a comprehensive weight loss program that includes:

    
  • Reduced caloric intake
  • Regular exercise and other behavior changes
  • Psychological counseling (if needed)
  • Prescription Medications

    Central Nervous System Medications

    Common names include:

        
  • Phentermine
  • Phendimetrazine
  • Diethylpropion
  • Phentermine plus extended release topiramate
  • Lorcaserin
  • These medications act on your brain to suppress your appetite. Phentermine, phendimetrazine and diethylpropion are only recommended for short-term use (a few weeks).

    Possible side effects include:

        
  • Phentermine:     
  • Elevation of blood pressure
  • Heart problems
  • Sleeplessness
  • Nervousness
  • Headache
  • Dry mouth
  • Problems with stomach or intestines such as nausea, diarrhea , or constipation
  • Difficulty urinating
  • Rash
  • Restlessness
  • Lightheadedness
  • Phendimetrazine     
  • Sleeplessness
  • Nervousness
  • Diethylpropion:     
  • Nervousness
  • Sleeplessness
  • Headache
  • Lightheadedness
  • Phentermine plus extended release topiramate     
  • Elevation of blood pressure
  • Heart problems
  • Sleeplessness
  • Nervousness or irritability
  • Numbness or tingling of skin
  • Change in taste
  • Depression
  • Lorcaserin     
  • Lightheadedness
  • Headache
  • Fatigue
  • Nausea
  • Dry mouth
  • Constipation
  • Back pain
  • Cough
  • Fat Absorption Blockers

    Common names include: orlistat, available as;

        
  • Xenical (prescription)
  • Alli (over-the-counter)
  • Taken at a dose of 120 milligrams 3 times a day, Xenical prevents ingested fat from being absorbed by blocking digestive enzymes. About 30% of the fat you eat will remain in your bowels. In some, the fat is excreted by the body between bowel movements as an oily discharge. It is recommended for long-term use (up to about 2 years). Orlistat is also available in a 60-mg over-the-counter form, called Alli.

    Possible side effects include:

        
  • Staining of underwear
  • Gas
  • Pressure to empty bowels
  • Leakage of stool
  • Increased frequency of bowel movements
  • Severe liver damage (rarely)
  • Over-the-Counter (OTC) Medications

    OTC medications advertised as promoting weight loss are generally considered ineffective. Some have led to serious side effects. Do not use over-the-counter or herbal remedies without talking to your doctor.

    Special Considerations

    If you are taking medications, follow these general guidelines:

        
  • Take the medication as directed. Do not change the amount or the schedule.
  • Ask what side effects could occur. Report them to your doctor.
  • Talk to your doctor before you stop taking any prescription medication.
  • Plan ahead for refills if you need them.
  • Do not share your prescription medication with anyone.
  • Medications can be dangerous when mixed. Talk to your doctor if you are taking more than one medication, including over-the-counter products and supplements.