Hair sunscreen is a product designed specifically to offer UVA and UVB protection for the hair. Exposure to the damaging rays of the sun can cause hair to become dry, faded in color, and brittle. Sunscreens for hair generally contain many of the same active ingredients as sunscreens for the rest of the body. They are typically available as shampoos and conditioners, but there are also several leave-in products available. Hair sunscreen can help protect hair's color, as well as preventing the structural damage to hair follicles that can occur as a result of sun exposure.
Sun protection products for the hair and scalp should generally list a sun protection factor (SPF) rating on the bottle. Many hair products contain ingredients that are intended to block or reflect the passage of UVA/UVB rays, but it is believed that the most effective products are intentionally designed to offer sun protection. These products may contain active ingredients such as zinc oxide or titanium oxide, which generally rest on the surface of the hair follicle and reflect damaging ultra-violet rays. Other hair sunscreen products may contain ingredients believed capable of penetrating the hair follicle to offer more lasting sun protection. Hair sunscreen products that penetrate the hair follicle are often considered more suitable for protecting the hair from the periods of brief exposure that generally occur on a daily basis.
Conditioners and shampoos often boast some level of sun protection, and many such products claim to help reverse the damage already done to hair by sun exposure. Spray-on hair sunscreen products are often oil-based and can weigh hair down if applied too often or too heavily. Research seems to suggest, however, that sunscreen products for the hair and scalp are most effective if applied thoroughly and evenly to the hair. Some manufacturers offer gel-based products that claim to protect hair from the effects of the sun while preserving hair's body and appearance.
Experts typically advise choosing a hair sunscreen with an SPF of about 10. The level of sun protection offered is said to correlate to the length of time it takes one to experience sun burn without sun protection. Experts advise multiplying this length of time, which will vary on an individual basis, by the level of SPF protection offered by the sunscreen, to determine how often sunscreen should be re-applied. Prolonged sun exposure will generally require repeated applications of sun protection product for maximum safety.