Aydian Dowling is currently leading the annual "Ultimate Guy" contest held by Men's Health magazine. If he wins, he will be the first trans man to appear on the cover. Jason Robert Ballard/FTM Magazine hide caption

itoggle caption Jason Robert Ballard/FTM Magazine

Some men take testosterone hoping to boost energy and libido, or to build strength. But at what risk? iStockphoto hide caption

itoggle caption iStockphoto

There's more than one reason to aim for a good night's sleep. Charles Taylor/iStockphoto.com hide caption

itoggle caption Charles Taylor/iStockphoto.com

The active ingredient in Propecia, a baldness remedy approved by the Food and Drug Administration in 1997, is showing new promise as a way to prevent some prostate cancers. AP hide caption

itoggle caption AP