It really depends on how you look at the efficacy. 1/3 of patients lost more 10% body weight and 1/ of patients lost more than 5% on Lorcaserin. It has been demonstrated that patients who lost more than 5% body weight showed improvement in caridovascular and diabetic risk factors taking Lorcaserin (of course same level of improvement can also be achieved without the drug if you lose 5% of weight). We are not talking an obesity drug for the sake of cosmetic propose. The marketing strategy is to imrove overall health. If you go to your primary care physicians and he finds your BMI and caridovascular markers slightly above average its a drug they can prescribe rather just ask you to exercise more and eat less fat. You really don't need a drug that makes you lose tons of weight with a lot of "tolerable" side effects unless your are morbidly obese.