Can you tell me what is the best prescription weight loss pill?

Options: I can’t personally make recommendations for weight loss products but the following are FDA approved: Alli, Xenical (orlistat),Meridia (sibutramine), Adipex-P (phentermine) and Sanorex (mazindol).

Modest benefit: There are two weight loss medications approved for long term use in the US, Qsymia and Belviq (lorcaserin). Both cause a modest amount of weight loss (app 8-10% body weight loss) but are usually effective in only 50-80% of people who take them. Victoza is a diabetic medication that is being reviewed by the FDA for weight loss. It will likely be effective in over 85% of people.