Roughly two-thirds of men will start experiencing hair loss by their 30s . Some guys embrace the change and shave it all off— Pitbull’s bald look is still iconic to this day. Others might look for ways to slow down hair loss. If you’re Team Hair, seeing more strands on your comb than your head can be nerve-racking. Companies are capitalizing on the fear: selling serums, hair masks, shampoos that promise luscious locks. But does any of it actually work? There's no magic potion to help you regrow hair you've already lost, says Melissa Piliang, MD , dermatologist at Cleveland Clinic. Instead of gambling your time and money on products that may or may not work , she recommends focusing on these expert-approved strategies. What to Do If You’re Losing Hair THERE ARE MANY reasons guys prematurely bald. Some of it is from genetics or a health condition. For example, the autoimmune condition called alopecia areata causes hair loss. Then there’s lifestyle factors you can control.…