Medication for Obesity

Hormone-receptor agonists help aid weight loss by mimicking natural hormones in the digestive tract that regulate appetite and satiety, which means feeling full. They include GLP-1 agonist receptors such as tirzepatide, commonly known as Zepbound, semaglutide, commonly known as Wegovy, and liraglutide, known as Saxenda. GLP-1 agonists 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 prevents the liver from releasing excess glucose.

These medications also slow the emptying of the stomach, helping people to feel full longer after eating. Similarly, tirzepatide (Zepbound), is a GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) agonist. Tirzepatide works by activating both hormones, GLP-1 and GIP, to reduce appetite, as well as reduce food intake, body fat, and body weight.

Semaglutide and tirzepatide are self-injected weekly and liraglutide is self-injected daily under the skin. Side effects may include nausea, diarrhea, vomiting, and constipation. Semaglutide in the form of Wegovy has been shown to help reduce cardiovascular events in people with cardiovascular disease who are also overweight or obese, but who do not have diabetes. Hypoglycemia, or low blood sugar, can occur in people who take these medications in combination with sulfonylurea medications or insulin for diabetes.

Anorectic medications, such as phentermine (Adipex-P or Lomaira), work by reducing appetite. Taken by mouth, these medications tell the brain you’re full after you’ve eaten only 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.

Clinicians  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.

Another 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 providers occasionally recommend lipase inhibitors 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.