Arena Pharmaceuticals won approval from the Food and Drug Administration for its obesity drug, Belviq, in June, and its share price has jumped more than 380% year to date. Shareholders have undoubtedly enjoyed this return, but where will Arena go from here? How will Belviq fare against VIVUS' rival obesity drug, Qsymia? Will Orexigen's weight loss candidate, Contrave -- which could be FDA-approved soon -- ultimately prove to be the long-term winner in this market?

These are difficult questions to answer, but understanding the science behind these drugs can help you read through press releases and make better investing decisions. In this video, health care analyst Max Macaluso discusses how Belviq works biologically and notes a few things to watch in Arena's upcoming post-marketing studies.

Arena is confronting significant challenges as it prepares to launch Belviq in 2013. In our brand new premium research report on Arena Pharmaceuticals, senior biotech analyst Brian Orelli walks investors through both the opportunities and threats facing the company. Since key news can develop quickly, we're also including a full year of updates for those who sign up. Click here now to learn more.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.