12 Common Skincare and Cosmetic Ingredients Derms Want You to Avoid

Chemical Sunscreen

A recent study showed that six common chemical sunscreen ingredients absorb into the bloodstream and greatly exceed levels considered safe. "One ingredient—oxybenzone—showed an absorption rate 188 times the safe level after one application," says Dennis Gross, MD, a dermatologist and dermatological surgeon. "After four applications, absorption increased 500 times the safe level. All chemicals stayed elevated in the blood anywhere from one to 21 days, depending on the chemical sunscreen ingredient."

It has been well established that oxybenzone is an endocrine disrupter, which can have serious consequences on fertility. Moreover, chemical sunscreen should be avoided during pregnancy as it has been linked to birth defects. The American Academy of Pediatrics also recommends that parents don't use sunscreens with oxybenzone on kids. Instead, Dr. Gross recommends opting for mineral sunscreen, which sits on the surface of the skin and isn't absorbed. The active ingredients in these safe sunscreens are zinc oxide and/or titanium dioxide.

RELATED: 15 Best Mineral Sunscreens

Methylisothiazolinone

Methylisothiazolinone is a preservative found most often in water-based products like shampoos and cleansers. "Even though it's used in small concentrations, it's still a strong allergen and can cause burning, itching, or even hives," says Marie Hayag, MD, a dermatologist and founder of 5th Avenue Aesthetics. "Those with sensitive skin should avoid this ingredient altogether, especially when it comes to leave-on products."

Sodium Lauryl Sulfate

Sodium lauryl sulfate is a very common cleansing agent. "It's found in a wide array of personal care items, including shampoos, cleansers, and body washes," says Dr. Hayag. "It frequently causes irritation and can also elicit an allergic response in the skin. If SLS is not washed off properly, its residue can leave your skin dehydrated and reduce the levels of ceramide in your skin." She suggests looking for products that have fatty alcohols instead. "Castile-based soaps or cleansers are good alternatives," she says.

Acrylates (Ethyl Acrylate, Ethyl Methacrylate, and Methyl Methacrylate)

Acrylates are mainly found in artificial nail products and false eyelashes where they're used as adhesives. They can cause contact allergies in a relatively high number of people, according to Dr. Hayag. "Different acrylates are also associated with different concerns, including possibly being carcinogenic," she says. "Since practically all artificial nail products contain some form of acrylate, it's best to either avoid them altogether, or at least lower your use of them."

Parabens

Parabens are one of the best-known no-no ingredients, and yet these preservatives, derived from petroleum, are still incredibly pervasive. Not only are there links to breast cancer, they are known endocrine disruptors, meaning they mimic estrogen in the body, which can lead to hormonal imbalances and infertility.

"Parabens can be listed under different names, but the most common are methylparaben, propylparaben, butylparaben, and ethylparaben," says Debra Jaliman, MD, a dermatologist and author of Skin Rules: Trade Secrets from a Top New York Dermatologist. According to Dr. Jaliman, parabens are particularly common in makeup and moisturizers.

Coconut Oil

Coconut oil has been widely touted as an effective spot treatment for acne (among many other things), but Howard Sobel, MD, founder of Sobel Skin and attending dermatologist and dermatologic surgeon at Lenox Hill Hospital, says it actually makes the breakout worse by clogging surrounding pores. While he advises against applying pure coconut oil, he also advises against products—like face masks and moisturizers—formulated with coconut oil. "Even in those small concentrations, it can still be irritating, so it's better to just avoid altogether."

Fragrances

Many of us consider a good smell a deciding factor when choosing skincare, but we should actually be making sure that no synthetic fragrances have been added before sniffing anything. "The vast majority of products contain purely chemically produced fragrance compositions, which have been shown to cause allergic reactions on the skin, along with headaches, allergies, dizziness, rashes, cough, skin irritation, pigmentation, and hyperactivity," says Anne-Claire Walch, PhD, pharmacology expert and founder of Brûmée.

"Manufacturers use thousands of fragrance components in their products, and unfortunately, there's no regulation to make it mandatory to list all components."

Formaldehyde

Formaldehyde is popular in hair straightening products, nail polish, and other cosmetics, but Dr. Sobel says it should definitely be avoided, especially in skincare. "It's sometimes used as a chemical preservative to prevent bacterial growth, but if humans are exposed to high amounts of this, it has been thought that it puts you at higher risk for developing cancers," he says.

Toluene

Toluene is a chemical commonly found in nail polish and hair dyes. "It's a volatile petrochemical solvent that can be toxic to the immune system and can cause birth defects," says Michele Green, MD, a cosmetic dermatologist.

Phthalates

Used in cosmetics, primarily in fragrances, phthalates can also be found in skincare products. "They're known endocrine disruptors, which also cause hormonal and reproductive problems and birth defects," says Dr. Green.

Triclosan

Triclosan is something many of us have been heavily exposed to, as it's found in antibacterial soaps. "Triclosan should be avoided because it causes antibiotic-resistant bacteria, and it's also known to disrupt the endocrine system," says Dr. Green.

Mineral Oil

This common ingredient found in your makeup, SPF, and cleansers is a byproduct of petroleum. "It can contain carcinogenic chemicals, which as we've learned from formaldehyde, is thought to put humans at a higher risk for cancer if used in high amounts," says Dr. Sobel.