While the pharmaceutical space has been generating hefty returns for investors since the start of the year, shares of Teva Pharmaceuticals (NYSE:TEVA) are up a mere 2.7%. Compare that with Dow component Pfizer, which has soared almost 14%, and generic-drug maker Mylan, up 42% since the start of 2013, and it's clear that something serious is muting Teva's growth. In the following video from The Motley Fool's health-care show Market Checkup, analysts David Williamson and Max Macaluso discuss the major competitive threats confronting Teva today.

David Williamson owns shares of Pfizer. Max Macaluso, Ph.D., has no position in any stocks mentioned. The Motley Fool recommends and owns shares of Momenta Pharmaceuticals. Try any of our Foolish newsletter services free for 30 days. We Fools don't 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.