Grooming products tend to make big promises: They’ll erase wrinkles, fix the bags under your eyes, lift sagging skin, take a decade’s worth of wear off your face. We can see why you’d be skeptical. But there is one area where the right product can deliver real results: your hair. A good shampoo, a new conditioner, or a dab of a particular gel can make a noticeable difference, says New York City stylist Kristan Serafino. “They’ll hydrate the hair, making it look plumper and shinier,” she says. We decided to test that proposition by asking a handful of men to try these new hair-care goods for two weeks. The unanimous verdict: softer, healthier, fuller hair. Here, a simple regimen that works.