Chances are, you’ve already put something on your skin today that can promote breast cancer. It could be in your soap, your shampoo, your shaving cream, your makeup, your moisturizer, your sunscreen—or all of the above.

We’re talking about parabens, the most widely used class of chemical preservatives in cosmetics and personal-care products. They’re hormone disrupters, suspected of increasing breast cancer risk. They mimic estrogen, producing similar effects that can cause human breast tumor cells to multiply.

Until now, though, the risk seemed relatively small, because parabens appeared to act only as very weak hormone disrupters. While avoiding them in your sunscreen and other products might be prudent, there wasn’t strong evidence that they could play a significant role in causing breast cancer cells to proliferate.

But a new study finds that, under the right circumstances, these chemicals are 100 times more potent at stimulating breast cancer cell growth in the presence of growth factors.

Find out how to protect yourself…


Dale Leitman, MD, PhD, a gynecologist and adjunct professor of nutritional sciences and toxicology at University of California, Berkeley, and his research team tested parabens not by themselves, as other studies have done, but in combination with another compound made by the body.

They looked at heregulin, a naturally occurring growth factor made by breast tissue. In the lab, they combined breast cancer cells, parabens and heregulin…and compared that with breast cancer cells treated just with parabens.

The result: As other studies have found, parabens triggered estrogen receptors to turn on genes that make the cancer cells proliferate. But here’s the really disturbing part—parabens combined with heregulin were 100 times more potent! In other words, in the presence of heregulin, it took just 1/100 of the dose of parabens to get breast cancer cells to grow rapidly. The research is evidence that earlier studies of parabens and other hormone disrupters may have vastly underestimated the cancer risk by focusing on just one chemical at a time.

While more research is clearly needed, that doesn’t mean it’s too early to act. According to Dr. Leitman, women should minimize or avoid the use of parabens—especially anyone with a family history of breast cancer. In fact, this study also suggests that excessive exposure to parabens and other xenoestrogens (chemical compounds that imitate estrogen) might increase the risk for breast cancer in men—about 1% of breast cancers occur in men, and 90% of those are estrogen positive.

Dr. Leitman believes the same logic applies to other known hormone disrupters, such as phthalates, compounds added to nail polish, hair spray and other cosmetics. He plans to study the phthalate combination in future studies, and he expects a similar cancer-promoting effect in the presence of growth factors. “We expect the same effects as with parabens because phthalates show similar types of biological behavior,” he says.

In fact, parabens were never actually shown to be safe, according to Tracey J. Woodruff, PhD, MPH, director of the program on reproductive health and the environment at University of California, San Francisco, who is not affiliated with the study. “I don’t think there was enough scientific evidence to show that parabens were ‘safe,’ only that they were not shown to be harmful. Studies often do not account for the way real bodies work and people live. Thus the quality of the studies and the evaluation are often insufficient to say one way or the other. Proving that something is safe is a pretty high bar.”

If you’re ready to get hormone disrupters off of your skin and out of your body, read on.


A segment of the cosmetic and personal-care product industry has caught on to concern over parabens and other potentially toxic chemicals and has been creating “paraben-free” and “phthalate-free” products for several years. But these hormone-disrupting chemicals are still perfectly legal to include in products, and they are still widespread.

While the FDA does not require premarketing safety testing of any chemicals in cosmetics, the federal Fair Packaging and Labeling Act (FPLA) does require manufacturers to list all ingredients so consumers can decide for themselves which products—and ingredients—they want to steer clear of. Here’s how…

To avoid parabens…

• Look for products that are labeled “paraben-free.”

• If you don’t see “paraben-free” on the label of your cosmetics and personal-care products, read the ingredient lists and avoid products that list methylparaben, propylparaben, butylparaben or benzylparaben—the most commonly used parabens—in the ingredients. Also avoid anything that ends in “paraben.”

To avoid phthalates…

• Look for products labeled “phthalate-free.”

• If you don’t see “phthalate-free” on the label, check the ingredients list for dibutyl phthalate (DBP), dimethyl phthalate (DMP), diethyl phthalate (DEP) and anything that ends in “phthalate.”

• Go fragrance-free. The FPLA does not require the listing of individual fragrance ingredients, and phthalates are commonly used in fragrances. So avoid products that include “fragrance” in their ingredient list.

• You can seek out “phthalate-free” fragrances but will have to rely on the manufacturer’s word. One good bet: Choose products that rely on essential oils or other natural-based, rather than synthetic, fragrances.


You could wait until the thousands of chemicals that can be added to skin products are tested, but don’t hold your breath. Most have never been tested and will never be tested. Plus, even when a chemical such as a paraben or a phthalate has been removed, the replacement chemical may turn out to have similar effects, says Dr. Leitman. His advice—minimize exposure to products that contain ingredients that may affect hormones. That’s why many people choose to protect themselves by minimizing exposure to synthetic chemicals in personal-care products. Here are some tips…

• Limit your products to those with just a few ingredients—and research them.

• When in doubt, check your product, or the product’s company, against databases that track safe or unsafe use of chemicals in cosmetics and personal-care products such as the Environmental Working Group Skin Deep Database, Campaign for Safe Cosmetics or the Good Guide.

• Don’t rely solely on a label that claims a product is “100% natural” or “made with organic ingredients” or some other variation of some healthful-sounding claim. “There is no guarantee that products labeled ‘natural’ or ‘organic’ are safe,” says Dr. Woodruff.

• Consider making your own cosmetics or skin creams (see below).

And lastly, get involved and vote, according to Dr. Woodruff. There are literally thousands of chemicals in cosmetics and personal-care products, and, unlike foods or drugs, there is no regulatory requirement that they be tested before they go on sale. Says Dr. Woodruff, “The government should require that the burden be on the manufacturers to make sure these chemicals are safe before they go on the marketplace.”

To learn more, see Bottom Line’s Squeaky Clean…and More Likely to Get Breast Cancer?, Dangerous Phthalates in Your Toiletries and Cosmetics? and, for natural alternatives, Five Ways to Improve Your Skin and Save Money: DIY Body Lotions.