While most of us buy cosmetics assuming they will benefit our skin or hair in some way, a new study has revealed that the number of reports about the adverse reactions to cosmetic products more than doubled last year when compared to 2015,   with hair care products being the biggest offender.  

The study was conducted by Northwestern University researchers after they examined data on side effects reported to the U.S. Food and Drug Administration (FDA) from 2004 to 2016. Products such as makeup, sunscreen, tattoos, hair color, perfume, shaving creams and baby care items were studied and overall, there was a total of 5,144 adverse events, with an average of 396 a year, researchers reported in JAMA Internal Medicine.

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"The FDA has much less authority to recall cosmetics from the market in stark contrast to drugs or medical devices," said corresponding author Dr. Steve Xu, a resident physician in dermatology at Northwestern University Feinberg School of Medicine. "It's harder for the FDA to get harmful cosmetics off the shelves."

The study suggested that cosmetics are underregulated in the United States, and there's no solid system in place to ascertain when personal care products are harmful, due to which the current data sources to track product safety are significantly limited.

Xu added that he suspects many events are not reported by consumers or doctors.

"Here is a $400 billion industry with millions of products and multiple controversies, but we only had about 5,000 adverse events over the course of 12 years," Xu said. "That's very, very underreported."

For the study, Xu and his colleagues examined adverse events data in the FDA's Center for Food Safety and Applied Nutrition’s Adverse Event Reporting System (CFSAN), a repository made publicly available in 2016. It includes voluntary reports of side effects submitted by consumers and health care professionals.

In 2014, the FDA had begun investigating WEN by Chaz Dean Cleansing Conditioners after receiving 127 consumer reports. The FDA later learned that the manufacturer had already received 21,000 complaints of alopecia and scalp irritation. The product still remains on the market with the FDA requesting for additional consumer reports. 

The most common complaints in the database were for hair care products, skin care products or tattoos, the study found. The number of overall adverse events jumped from 706 in 2015 to 1,591 in 2016, with hair care products seeing the largest increase. Baby products, unclassifiable products, personal cleanliness products, hair care products and hair coloring products had the highest proportion of self-reports of a serious adverse health outcome, such as serious injury, death or disability.

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Most health issues involved rashes, hair loss, and other dermatological problems, although more serious illnesses such as cancer or severe allergic reactions also were reported.

Limitations of the study include the lack of data on what caused side effects, the authors note. Researchers were also unable to distinguish between reports from consumers and from health professionals.

Under current law, the cosmetics industry is largely self-regulated, Dr. Doris Day, a dermatologist at Lenox Hill Hospital in New York City said in the study.

"It is left with all of these products for the companies to police themselves, and I think in many ways the market polices them when things don't go so well," Day said.