
They promised that you'd never have to shave or wax again—with no ingrowns, no bumps, and no stubble. That's why laser hair-removal gadgets were the first of the at-home devices that anyone really got excited about. But then there was the sad reality: They took forever to work and delivered only so-so results. Now there's a new generation that claims to be better. Dermatologists say the Tria Hair Removal Laser, which uses a diode laser, has the most science behind it. Like professional lasers, it works only on dark hair and fair skin, and it can take months to yield results. "It damages stem cells in the hair follicle," says Neil Sadick, a dermatologist in New York City. "It slowly thins out hair. You may or may not ever achieve total hairlessness." Thin skin—above the lip, in the armpits, and along the bikini line—tends to get smoothest, fastest, says Sadick. Our tester used the Tria once every two weeks for three months before her armpits were hairless, and each session hurt (it feels like a rubber band snapping against your skin). She now does touch-ups every month or so. (Each underarm takes about five minutes. If you want to tackle your legs, count on about an hour each.)