Endocrine Disruptors in Shampoos

In our final post in the series of Endocrine Disruptors in personal care products, Biology graduate Isaac Han and Finance graduate Kristin Peters researched the chemicals most often found in top brands of shampoos. Although there has been recent news that using this product as often as we do may not be necessary, almost everyone will keep a bottle in their showers. The project was part of the co-listed spring course, Marketing/Biology 597. Kristin shares:

Personally, I love shampoo. I could spend hours walking through the aisles of a typical drugstore sniffing all the different scents and brands. A couple of years ago, I wouldn’t have believed you if you told me that there could be chemicals in those shampoos that could contribute to breast cancer.

For shampoo, there are a few specific things to look out for in the ingredients list. Number one is fragrance. The word “fragrance” can essentially mean anything, and many personal care product ingredient lists often use it in place of listing chemicals known to have negative health effects. One family of chemicals that are often used to keep the odor attached is phthalates, which are known endocrine disruptors. Phthalates are also used to soften plastic, and are easily absorbed through the skin and found in many shampoos and other cosmetics. They are known to disrupt the reproductive systems and interfere with the production of testosterone and estradiol.

Another group of chemicals to look out for are parabens. Parabens are estrogen mimics and have been linked to breast cancer in several studies. The same parabens that have been used in cosmetics and body care products have been found in tumors and urine samples of cancer patients. They are used as preservatives, but can enter the body through skin contact. Obviously, there is a lot of skin contact when it comes to shampooing your hair.

The next time you run out of shampoo and head to the store, before you start sniffing all the different scents, turn the bottle around and check out the ingredients to better protect yourself!