An injectable drug commonly used for diabetes, Byetta, is getting a lot of attention for it's effects on weight loss. Byetta belongs to a class of medications known an incretin mimetics. The active ingredient in Byetta, exenatide, is an amino acid that was originally isolated from the salivary gland of the Gila lizard.
The clinical trials for Byetta did show a statistically significant weight loss in patients versus no treatment. In fact, the trials showed on average of 5-10 pounds of weight loss. It appears that there are several ways that Byetta works to stimulate this weight loss. It is thought to work by slowing the emptying of food in the stomach, increasing the feeling of fullness and suppressing appetite.
Evidence suggests that exenatide (Byetta, Bydureon) and drugs like it such as Victoza can help obese patients lose an average of 6 to 8 pounds over about 6 months. This is about the same as weight loss seen with most Rx weight loss drugs.
Currently, these drugs are only recommended as an option for overweight patients WITH type 2 diabetes on other antidiabetes meds, but who need better glucose control. It is not recommended for weight loss in patients who do not have diabetes as it’s too early to suggest that. There also are some potentially dangerous side effects to incretin mimetic drugs.
They’re associated with pancreatitis and the long-term effects in patients without diabetes is not known.
In addition, nausea and GI upset are often a problem. They also are not very cost effective for how well they work. They cost $200/month or more, are prescription only, and most insurances would not pay for they if they are being used for weight loss.