Eli Lilly (NYSE:LLY) currently has several blockbuster drugs on the market -- but lookout investors, there are patent expirations aplenty for this pharma giant ahead. Much like Merck (NYSE:MRK), which is dealing with the recent loss of exclusivity for its top-selling drug Singulair, Lilly has to rely on its pipeline to quickly produce drugs with massive market opportunities. In this video, health-care analyst Max Macaluso dives into the company's most worrying patent expiration of 2013.

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.