The Top 4 Categories of Cosmetic Ingredients to Avoid

Every other day there is another common cosmetic ingredient we are being told to avoid if we don’t want cancer or some other potentially terminal illness. These claims are sometimes based on years of extensive research demonstrating negative outcomes at various levels of exposure. BUT sometimes *or a lot of the time) it is based on 1-2 studies with small sample sizes that end in the phrase “but more research needs to be done to determine X”, combined with a lot of propaganda and or hysteria.

For the record, if you see a sentence remotely like that in the conclusion of a study then it is likely that it was published to spur additional research in the area rather than to offer definitive results or outcomes associated with exposure to a specific substance. Let’s jump right in! We began by trolling the web for lists of “dangerous cosmetic ingredients” in order to generate a comprehensive list of the “usual suspects.” We found that the “bad ingredients” generally fall into the following 4 categories.

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Endocrine Disruptors

Endocrine disruptors are chemicals that may interfere with the body’s endocrine system and produce adverse developmental, reproductive, neurological, and immune effects in both humans and wildlife. A wide range of substances, both natural and man-made, are thought to cause endocrine disruption. When absorbed in the body, an endocrine disruptor can decrease or increase normal hormone levels, mimic the body's natural hormones, or alter the natural production of hormones.


To our surprise carcinogens were secondary to endocrine disruptors. A carcinogen is any substance that promotes and/or encourages cancerous growths. Carcinogenic substances can be naturally occurring or man-made. For example, Aflatoxin B1, which is produced by the fungus Aspergillus flavus growing on stored grains, nuts and peanut butter, is a potent, naturally-occurring microbial carcinogen. Certain viruses such as hepatitis B and human papilloma virus have been found to cause cancer in humans. In this article we will focus on substances that could cause cancer.

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Birth Defect Inducers

A birth defect is a problem that happens while a baby is developing in the mother's body. Most birth defects happen during the first 3 months of pregnancy. One out of every 33 babies in the United States is born with a birth defect. “Birth defects” is a very broad category to describe, as many things can lead to birth defects. Here we are concerned with defects due to chemical exposure. Note that ingredients that can cause birth defects can be naturally and/or synthetically-derived.

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Environmental Hazards

Some substances found in cosmetics can lead to disruptions in the water table, wildlife, and/or our lived environment. Chemicals commonly found in cosmetics can affect reproduction in animals, harm development in amphibians and crustaceans, and induce genetic abnormalities. For example, plasticizers interfere with the functions of hormone systems, and have shown to bioaccumulate in organisms. Meaning that the chemical components that are found in many cosmetic products do not break down, but instead accumulate. Cosmetic chemicals that have been introduced into the aquatic system are transferred to other regions through rain and have been found in oceans, rivers, streams, and agricultural soil.











  10. Barrett, Julia R. “The ugly side of beauty products.” Environmental health perspectives vol. 113,1 (2005): A24. doi:10.1289/ehp.113-a24

  11. Yazdankhah SP1, Scheie AA, Høiby EA, Lunestad BT, Heir E, Fotland TØ, Naterstad K, Kruse H., Triclosan and antimicrobial resistance in bacteria: an overview. Microb Drug Resist. 2006 Summer;12(2):83-90.

  12. Lanigan RS; Cosmetic Ingredient Review Expert Panel., Final report on the safety assessment of PPG-11 and PPG-15 stearyl ethers. Int J Toxicol. 2001;20 Suppl 4:53-9.