Sun, a dry climate, abuse from hot dryers and irons, and heredity can all contribute to dry hair. “But as with your nails, which are also made of keratin, you can restore moisture to hair,” says dermatologist Marianne O’Donoghue.

Maintenance: Shampoo twice a week, using products containing moisturizing ingredients, like panthenol and ceramides. Condition after every shampoo. “Hair can absorb only so much conditioner, so don’t feel the need to slather it on,” says Amanda B. Once a month, use a deep-conditioning mask.

Styling: Try to minimize the use of hot styling tools. When you do blow- dry, straighten, or curl, apply a silicone-based cream or serum to tame frizz, promote shine, and shield the hair from heat.

Common Misconception: Clarifying shampoo makes dry hair look even drier. “In fact, dry hair holds more product residue because it’s more porous,” says Barbara Eisenberg, a stylist at Sofia’s Salon & Spa, in Boca Raton, Florida, so using a deep-cleansing shampoo once or twice a month lifts that heavy buildup and makes it shine like new.

What’s to Love: You don’t have to wash your hair as often.

RS Picks for Dry Hair

Marc Anthony Ultimate Moisture Replenishing Shampoo (($8 at drugstores and www.ulta.com) uses soy and shea butter to repair and hydrate.

Pureology HydraCure Intense Moisture Hair Masque ($45, www.pureology.com for salons) contains shea, mango, and avocado butters to deeply moisturize dry hair.

Ojon Shine & Protect Glossing Mist ($28, www.sephora.com) uses plant extracts to combat frizz.