Eli Lilly (NYSE:LLY) is one of today's biggest players in the erectile dysfunction space. Its drug Cialis garnered more than $1.9 billion in 2012, but how important is this single therapeutic to Lilly's total business? What are the competitive dynamics of the erectile dysfunction market, and how do Pfizer's (NYSE:PFE) Viagra and VIVUS' (NASDAQ:VVUS) drug Stendra compare to Cialis? In this video, health care analyst Max Macaluso examines these issues for investors.

Max Macaluso, Ph.D. has no position in any stocks mentioned. The Motley Fool has no position in any of the stocks mentioned. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.