Medication for Obesity

Anorectic medications, such as phentermine, or Adipex-P^®, work by reducing appetite. Taken by mouth, these medications tell the brain you’re full after you’ve eaten a small amount of food.

Anorectic medications are usually prescribed for less than three months. These medications can increase heart rate, cause seizures, and worsen mood disorders that aren’t controlled well with medication. Other side effects may include dry mouth or mild anxiety.

Serotonin inducers reduce appetite by blocking a hunger receptor in the brain called 5-HT2C. NYU Langone doctors may prescribe these medications for people who need to lose 5 to 10 percent of their total body weight. One commonly prescribed serotonin inducer, lorcaserin, also known as Belviq^®, has been shown to help people lose weight and maintain weight loss for more than two years.

Serotonin inducers are generally very well tolerated. However, these medications are not recommended for people who are taking selective serotonin reuptake inhibitors, or SSRIs, to treat anxiety or depression. Taken together, these medications may lead to a dangerous increase in serotonin levels in the brain, causing symptoms such as confusion, muscle spasms, tremors, and hypertension.

Doctors commonly prescribe combinations of medications to treat obesity. For instance, Qsymia^® combines the anorectic medication phentermine with the antiseizure medication topiramate, which enhances phentermine’s appetite-suppressing effect. Side effects of this medication, which is taken by mouth, may include mood changes and insomnia. Women who are pregnant should not use this medication because it can cause birth defects.

A newer medication, Contrave^®, combines the antidepressant bupropion with naltrexone, a medication used to treat substance abuse. This medication can cause mild nausea and fatigue.

Lipase inhibitors such as orlistat, also known as Alli^® or Xenical^®, block the body’s production of an enzyme called lipase, which aids in the breakdown and absorption of fat in the intestines. These medications, taken by mouth, prevent the body from absorbing fat, which is instead eliminated through stool.

Our doctors may recommend lipase inhibitors occasionally for people who are unable to avoid consuming foods that are high in fat. Side effects may include oily stools, diarrhea, bloating, and abdominal pain.

GLP-1 agonists, such as liraglutide, or Saxenda^®, mimic the action of GLP-1, a hormone made in the small intestine that is released shortly after eating. GLP-1 lowers blood sugar by triggering the production of insulin, a hormone that regulates blood sugar, and preventing the liver from releasing excess glucose. These medications also slow the emptying of the stomach, helping people to feel full for a longer period after eating.

GLP-1 agonists are injected daily under the skin. Side effects may include nausea, diarrhea, and vomiting. Hypoglycemia, or low blood sugar, can occur in people who take this medication in combination with sulfonylurea medications for diabetes.