i did-not sure how acurate the site is. there may be a lot of success stories but knowing my luck, i'll be the one to get cancer and lose my hair.
Report on Nioxin Ingredients, Side Effects and Usage by AskDocWeb
AskDocWeb: We do not recommend Nioxin because it is on the consumer list of products and chemicals known or suspected of causing cancer, birth defects and other negative health affects. The Breast Cancer Fund says no to the use of Nioxin, Friends of the Earth say no to the use of Nioxin, and Health Care Without Harm says no to the use of Nioxin.
further down the page:
We are not saying that Nioxin causes cancer, consumer protection groups are saying that one or more of the ingredients in it is known or suspected of causing cancer. In looking at that long list of ingredients the first one that draws attention is Sodium Laureth Sulfate. Several consumer protection groups have identified this as being a harmful ingredient. Toxicology research by the OSHA, NTP, and IARC supports the conclusions of the Cosmetic, Toiletry, and Fragrance Association (CTFA) and the American Cancer Society that pure Sodium Laureth Sulfate is not a carcinogen. The objection arises because Sodium Laureth Sulfate and products containing it have been found to contain low levels of 1,4-dioxane. The U.S. Environmental Protection Agency considers 1,4-dioxane to be a probable human carcinogen because of the observed increased incidence of cancer in controlled animal studies. Although the U.S. Food and Drug Administration encourages manufacturers to remove 1,4-dioxane, it is not required by federal law. The manufacturer of Nioxin has not made it clear if 1,4-dioxane is removed from their product or not.