they lose because the victoza kills their appetite. >> my appetite went away almost immediately. it just really stops what you eat, stops you overeating. which has been a huge, huge help. >> reporter: patients take victoza as a daily shot, and they have to stay on their diabetic diet. people are also losing weight on byetta, a sister drug to victoza, which is older and cheaper. the big question, what if you aren't diabetic, can you take these shots just for weight loss? >> there are a lot of doctors out in the community who are using victoza and byetta to help promote weight loss. >> is that a good idea? >> i think so. >> reporter: dr. hoffman says the weight loss itself can reverse type 2 diabetes before it ever starts. if insurance doesn't pay, people often shell out the $6,000 a year themselves because the results are that spectacular. >> i've told many of my patients that this drug is a miracle drug. because it works, has very few side effects, and the patients are thrilled with it. it changes their lives. >> wow.