Question: I’m now a believer and use a sunblock everyday on my face, neck and hands. I’ve been seeing ads for shampoos and conditioners with sunscreens. Should I use them to protect my hair from UV damage?
Answer: Hair is made of keratin, which is also found in skin. But the keratin in hair is dead– which is why you can cut it without pain. And because the hair shafts are dead, UV rays cannot cause cancerous changes. However UV rays can still damage the hair. Shampoos and conditioners with sunscreens are just rinsed out and cannot offer protection. Spray on sunscreens would have to leave a thick greasy film in order to genuinely block UV rays. FYI You will notice that hair care products with sunscreens don’t provide an SPF. This is because their protection cannot be measured the way it can be with the skin.
However, sunlight can definately affect the hair. It can create flattering highlights in natural hair , but can turn hair coloring products brassy. Color treated or relaxed hair ( eg Brazilian or Japanese hair straightening) can become dried out and fragile from a day at the beach. You need to protect the hair from heat, sunlight, chlorine from a pool or even salt from the ocean.
Sun protection for the hair starts low tech with a hat. A big, tightly woven straw hat will offer protection to your hair, face, neck and shoulders. I love my Tilley hats that provide a 55 SPF and some models are also repel bugs. After a long wet spring which is a bug paradise, this feature is especially welcome in my area this year. After a day in the sun, wash your hair with a shampoo formulated for color treated hair and apply a leave on a conditioner for 2-3 minutes. If you use a double process to lighten your hair, think about and nice big umbrella for a hair friendly day at the beach.