Shampoos with Hormones Linked to Girls' Early Puberty
An article in New Scientist (April 2, 2002) suggests that some shampoos may be causing premature sexual development in girls. These shampoos, mostly marketed to the African-American community, contain small amounts of estrogen. This estrogen can be absorbed through the skin. Often people undergoing hormone therapy use patches to deliver these hormones systemically so there is little doubt as to absorption through the skin.
The evidence that hormone shampoos and other hair products can cause premature puberty is not conclusive, though; still about half of the African-American girls in the United States are developing secondary sexual characteristics by age eight. Nearly half of African-American women use these hormone products on themselves and on their daughters.
Although the FDA regulates products that contain hormones, there is a loophole for hair products that were marketed before 1994. Five companies and perhaps more are still selling these estrogen-containing shampoos and conditioners.
Of course there is the possibility that other substances in the environment and even diet change could be at fault in the premature puberty of girls, but nothing looms as large as estrogens in hair-care products. Julia Brody, director of the Silent Spring Institute, says, "There is an increasing awareness that hormonally active compounds are present in cosmetic products."