"When you add the two together you get very, very good weight loss," said Dr. Louis Aronne, New York Presbyterian Hospital.
It worked for 57-year-old Gwendolyn Barton, who'd tried just about everything to lose her extra pounds.
"I've done diet, I've done exercise, I have done Weight Watchers. And none of it has ever helped me," said Barton.
Until she tried Qsymia. In one year, as part of a clinical trial, she dropped 50 pounds.
"I went from a size 14 to a size 6. It made me feel great," said Barton.
Prescription diet drugs have had a troubled past. Meridia was withdrawn in 2010, and Fenfluramine (an ingredient in the popular drug Fen-Phen) in 1997. Both were withdrawn because of heart-valve concerns.
But doctors say Qsymia is promising. Patients lost an average of 10 percent of their body weight while on the medication.
But it isn't as easy as just popping a pill. The drug has to be used in conjunction with a healthy diet and exercise.
For Gwendolyn Barton, it's all paid off.
"My blood pressure started to go down," said Barton. "I felt much better. I was able to do things with my grandkids, go to the park, just have fun."
The company that makes Qsymia, Vivus, hasn't released how much the pills will cost but most expect it to be priced in the same range as most diabetes medications.