In a study published in the New England Journal of Medicine, researchers say that the only injectable weight loss drug approved by the Food and Drug Administration (FDA) helps people to lose more than 12 pounds, more than twice as much as people taking a placebo.
The study is one of several that the FDA considered before approving the drug in 2014. It included data on 3,731 patients who were randomly assigned to take liraglutide or a placebo for just over a year. The trial continued to follow the patients for another year, and that data will be published soon.
Liraglutide is similar to an already approved drug to treat type 2 diabetes, but is used in higher doses for weight loss. The drug mimics the effects of a hormone that works in the gut to signal the brain that you’ve eaten enough and feel full. As a diabetes drug, it helps the beta cells in the pancreas release insulin to keep blood sugar levels in check. In the NEJM study, none of the patients had diabetes, although some were pre-diabetic, and the FDA says liraglutide for weight loss should not be used together with the diabetes drug, also made by Novo Nordisk.
According to the study’s lead author, Dr. Xavier Pi-Sunyer, director of the obesity research center at Columbia University, liraglutide works as well as phentermine-topiramate (Qsymia), which doctors believe works by suppressing appetite. They key to making any weight loss medication effective, he says, is combining it with diet and exercise changes as well, which is what the participants in the study did. One advantage of liraglutide is that it can be used by women in their child-bearing years.
So far, the side effects of litaglutide, which include nausea, diarrhea, gall bladder abnormalities and pancreatitis, were minimal and did not outweigh the benefits of weight loss. But in approving the drug, the FDA asked the company to continue to study the drug to ensure that the adverse events remain within an acceptable range.