"Pharmacy benefits managers (PBMs) are the main distributors of drugs to retail pharmacies and directly to consumers; in our view, the PBM sector is a must-have health care area for investors," says Stephen Leeb.

The editor of The Complete Investor explains, "Express Scripts (ESRX) is a leading and fast-growing pure-play PBM that has been generating impressive results and is undervalued relative to the industry.

"One striking health care trend in recent years has been a dramatic rise in prescriptions. For the 10 years ended in 2009, according to a government study, the number of prescription drugs dispensed in the U.S. rose 39 percent, while U.S. population growth was just 9 percent.

Most portfolios could benefit from a pharmacy supply play for defensive purposes, and Medco Health Solutions (NYSE: MHS) is worthy of consideration for this role. Medco Health is one of the largest pharmacy benefits managers in United States, with services provided to member health plans offered by unions, HMOs, and corporations, among other organizations.

Analysts like Medco's high account retention, new business wins, economies of scale, and the company's entry into the Medicare Part B segment with its acquisition of PolyMedica. The Reuters F2007/F2008 EPS consensus estimates for MHS are $3.60/$4.38.

The risks? Analysts have their eye on the increased market penetration of generic drugs and some pricing pressure in contract renewals. Also, the stock's PE ratio of 30 is high, even considering MHS's growth prospects, hence the stock is vulnerable to a pull-back. The problem with the 'buy on pull-back' tactic here is that MHS's pull-backs have been mild, so there's no guarantee of a 5% pull-back before a share purchase decision.