Merck, for its part, has long urged patients to stick with treatment, arguing that finasteride's rare side effects, when they do occur, generally lessen over time. If there's no improvement, then the company says to go ahead and quit taking the drug. In theory, everything***8212;hair density included***8212;will eventually revert to its pretreatment baseline.
But is that really true? Among the study dropouts, says Dr. Wessells, only half had seen full resolution of their symptoms 6 months after going off the pills. "It was always one of the strange things about that study," he says, "as to why these men didn't get better."
As more and more cases began surfacing of men who'd quit finasteride only to suffer severe and persistent sexual problems afterward, researchers at George Washington University and the Greater Baltimore Medical Center decided to survey a group of those self-reported victims of what was being called "post-finasteride syndrome," or PFS.