Fred Hassan's decision to put his money where his mouth is seems to have helped slow down Schering-Plough's (NYSE: SGP) post-Enhance slide. After losing nearly one-fifth of its value, the stock fell "only" 1.6% on Friday.

Hassan, Schering's CEO, announced on Friday that he plans to buy $2 million of company stock. He wanted to buy on Thursday, after the market pushed shares to $21.62, but legal experts worried that he'd run afoul of federal securities laws. Instead, he'll wait until after the Enhance data is presented at a scientific meeting in March.

The Enhance trial last week reported that although Vytorin -- a combination of Zetia and Zocor -- lowers LDL cholesterol levels more than using Zocor alone, the lowered cholesterol doesn't translate to less plaque in the arteries. Schering and Merck (NYSE: MRK) are marketing partners on Zetia and Vytorin, and Schering has taken the harder hit, possibly because Schering derives much more of its revenue from the cholesterol drugs than Merck does.

Hassan, who currently owns 2.6 million shares -- much less than 1% of the company -- says he plans to make his purchase no matter what the price of the stock may be. Seems like a bad investment idea to me, but he probably had to say what he did for the public-relations stunt to work.

As if to show that Hassan knows a good deal when he sees one, the press release touting this news pointed out that in 2003, Hassan bought more than $4.5 million worth of stock whose value had more than doubled before the sell-off. Maybe we should give Hassan a job at our Inside Value newsletter service.

The competing companies that make name-brand cholesterol-lowering drugs, mainly Pfizer (NYSE: PFE) and AstraZeneca (NYSE: AZN), haven't felt much of a boost from the Enhance study. Investors must be thinking that patients will be switching to generic statins, although doing so will leave a lot of patients not meeting their cholesterol-level goals.

I agree with Hassan that the media has overblown the results of the Enhance trial. The fact remains that Vytorin reduces LDL cholesterol levels more than statins do. But that doesn't necessarily mean Schering is a good buy. The public's perception of Zetia and Vytorin is going to drive sales, and in an election year, with Congress investigating the drugs from multiple angles, Schering and Merck aren't going to have the easiest time growing their sales.

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Fool contributor Brian Orelli, Ph.D., doesn't own shares of any company mentioned in this article. Pfizer is a pick of the Inside Value newsletter service. The Fool has a disclosure policy.