Express Scripts (ESRX)  investors need to consider some of the risks in buying shares of the company. In this video, Fool Jim Mueller outlines three risks to the company's future health. Acquisitions, for example, may be more difficult to come by as Express Scripts could be viewed as having a monopoly on the pharmacy management business. Will the economy discourage new customers? Will synergies be achieved with its acquisitions? Investors need to think about these matters before jumping in.