Many treatments that enhance the appearance of your hair can actually damage it, causing your hair to become dry and brittle. Follow these dermatologists’ tips to prevent dry, brittle hair: When dyeing your hair, stay ‘on shade’. Choose a dye within three shades of your natural color. Typically dyeing hair darker is better than lighter. Lightening your hair more than three shades requires higher volumes of peroxide, which causes more hair damage. Test store-bought hair color before using. Follow manufacturer’s instructions. If you develop a rash or redness, swelling, burning or itching, you are having an allergic reaction to the die. Do not dye your hair and consult your dermatologist for further allergy testing. Protect your hair from the sun. The sun can make your hair weak, dry, rough, faded and brittle. This is especially true if you dye, bleach or perm your hair. Wear a wide-brimmed hat when you go outside. Use caution when perming hair to prevent long-lasting damage. Set a timer