Here are the basics about each of the medicines below. Only common problems with them are listed.
These medicines should only be used with diet changes, exercise, and therapy.
Central Nervous System Medications
Glucagon-Like Peptide-1 (GLP-1) Inhibitors
Monoamine Oxidase Inhibitors (MAOI)
For children and young adults:
These medicines act on the brain to lower appetite. Lorcaserin is for long-term use. Phentermine, phendimetrazine, and diethylpropion should only be used up to a few weeks.
Some problems are:
This medicine can be used by adults and children over 11 years old. Xenical stops the fat a person eats from being absorbed by blocking digestive enzymes. About 30% of fat will stay in the bowels. In some people, the fat leaves the body between bowel movements as an oily discharge. It can be used long-term (up to about 2 years). Orlistat also has an over-the-counter form called Alli.
Some problems may be:
This medicine is used for chronic weight control in people who have at least one other weight-related problem. It works by making a person feel less hungry or fuller faster while eating. It is given as a daily shot. The dose is slowly raised to 3 mg a day.
Some problems may be:
This medicine is used for chronic weight control. It combines two drugs. It works by making a person feel less hungry or fuller faster while eating. The dosage is slowly raised from one to 2 tablets a day.
It should not be taken by people with poorly controlled high blood pressure, seizures, eating disorders ( anorexia or bulimia), opioid dependency, or alcohol and drug withdrawal. People who already take bupropion should not take this medicine.
Some problems are:
NOTE: This medicine may cause suicidal thoughts or actions.
Alli is the only OTC weight loss medicine that is helpful. Others have led to severe health problems. They should not be taken without talking to a doctor first.
Meridia (sibutramine hydrochloride): follow-up to an early communication about an ongoing safety review. US Food & Drug Administration website. Available at: https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm198221.htm. Updated September 9, 2013. Accessed February 23, 2017.
Meridia (sibutramine): market withdrawal due to risk of serious cardiovascular events. US Food & Drug Administration website. Available at: https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm228830.htm. Updated September 9, 2013. Accessed February 23, 2017.
Obesity. Merck Manual Professional Version website. Available at:
...(Click grey area to select URL)
Update December 2016. Accessed February 23, 2017.
Orlistat (marketed as Alli and Xenical): labeling change. US Food & Drug Administration website. Available at: https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm213448.htm. Updated September 6, 2013. Accessed February 23, 2017.
Pai You Guo, marketed as dietary supplement—recall. US Food & Drug Administration website. Available at: https://www.fda.gov/Safety/MedWatch/SafetyInformation/SafetyAlertsforHumanMedicalProducts/ucm190531.htm. Updated August 29, 2013. Accessed February 23, 2017.
Prescription medications for the treatment of obesity. National Institute of Diabetes and Digestive and Kidney Diseases. Available at: https://www.niddk.nih.gov/health-information/health-topics/weight-control/prescription-medications-treat-overweight-obesity/pages/facts.aspx. Updated July 2016. Accessed August February 23, 2017.
Weight loss medications for obesity in adults. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T361156/Weight-loss-medications-for-obesity-in-adults. Updated May 27, 2016. Accessed February 23, 2017.
Weight loss medications for obesity in children and adolescents. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T474269/Weight-loss-medications-for-obesity-in-children-and-adolescents. Updated January 27, 2016. Accessed February 23, 2017.
9/17/2010 DynaMed Systematic Literature Surveillance http://www.dynamed.com/topics/dmp~AN~T116362/Weight-loss-medications-withdrawn-from-market: James WP, Caterson ID, Coutinho W, et al. Effect of sibutramine on cardiovascular outcomes in overweight and obese subjects. N Engl J Med. 2010;363(10):905-917.
Last reviewed November 2019 by
EBSCO Medical Review Board Daniel A. Ostrovsky, MD
Last Updated: 2/5/2021