Myth: Hair gets used to a product.

False. But there are other reasons you may need to change your shampoo, conditioner, or styling products--such as pregnancy, a change in seasons, or getting a new cut or color, says Gerard Kierans, owner of Easel Hair Studio in Georgetown.

Myth: Rinse your hair in cold water to prevent frizz.

False. "The only thing you can get from rinsing your hair in cold water is a chill," says Kierans. Cold water does make the hair cuticle contract for a second, but as soon as your body temperature returns to normal, so will your hair. While this may prevent a little frizz, the benefit may not be worth it.

Myth: Home cocktails with vodka, mayonnaise, or beer are great for hair.

False. There might be some ingredient in vodka, mayonnaise, or beer that's great for hair, but today's products use the best of those ingredients without the smell, funny texture, or hassle. "If there's any truth to it, you know the product people have researched it," says Kierans. "Put mayonnaise on your sandwich and something else in your hair."

Myth: Condition just the bottom part of your hair to avoid buildup.

False. "You're also conditioning your scalp," says Renee Burgess, a stylist with Eclips in McLean. "Just like your hands can get dry, your scalp can get dry." And conditioning hair from top to bottom brings the pH level back to normal and closes down the cuticle, making hair softer and shinier.

Myth: Baldness comes from yourmaternal grandfather.

False. It's genetic--period--and can come from either your mother or your father, says Arlington dermatologist Michelle Rivera. Genetics also determines whether it's male or female pattern hair loss.

Myth: Lemon juice lightens hairsafely and naturally.

False. Lemon juice will lighten hair, but it's drying and damaging. "You also have no control over how much or how little the hair lightens," says Kierans. "It's possible you can get blotchy color."

Myth: Just like skin, hair needs sunscreen.

True. "But don't just put sunscreen in your hair," says Burgess, who suggests using a hair product with sunscreen init. She recommends Grund Smooth, a leave-in conditioner with sunscreen and a chlorine blocker.

Myth: Baby powder acts like a dry shampoo.

True. Baby powder soaks up oil in your scalp, says Scott Palmer, owner of Lehman LaRue on Kent Island, Maryland. Don't want the white tinge of powder in your hair? Try one of the colored hair powders like the line from Bumble & Bumble.