But a new generation of researchers, using careful study designs and pure pharmaceutical yohimbine - nothing else - have shown that the drug really does seem to work for a small but consistent portion of the male population. It doesn't work as well as those fevered early reports claimed, but it does seem to work.

In one study, a team of researchers from Kingston General Hospital and Queen's University, in Ontario, tested the drug on 48 men who'd met strict criteria showing that their erection problems were psychogenic in origin, rather than being caused by any physical problem. For ten weeks, the men were given either yohimbine (18 milligrams daily, in the form of a 6-milligram tablet three times a day) or an identical-looking but totally inactive placebo.
Overall, the researchers found, 46 percent of the men taking yohimbine noticed either complete or partial improvement in the rigidity of their erections.

(Only 16 percent of the placebo group noticed any improvement.) Interestingly enough, these same researchers also tested yohimbine on a group of men with organic impotence and found it was almost equally effective-43 percent ofthese men also reported some improvement, including 20 percent who claimed com¬plete recovery. (Just to confound matters, 27 percent also responded to the placebo, however.)

"Until other pharmacological substances have been tested in controlled trials, yohimbine should be considered among the first treatment options for psychogenically impotent patients," the researchers concluded.