In the world of irritating skin ingredients, there are, of course, the major players that everyone knows to be wary of. (Retinoids, we’re looking at you.) But there are also some other, very popular skin-care ingredients that cause allergic reactions —ones that you might never think could be problematic. Here, dermatologists weigh in on these sneaky suspects and share the ingredients that are pretty much a guaranteed safe bet for skin.
5 common irritants in skin-care products
Neomycin
Allergies to neomycin, one of the active ingredients in Neosporin, are more likely than many think, says New York City board-certified dermatologist Dr. Robyn Gmyrek; it’s one of the more common allergens in skin-care products. Some people are also allergic to bacitracin, another of the active ingredients in the formula. “People are using Neosporin to treat a wound or cut. They start experiencing the topical symptoms of an allergic reaction—redness, tenderness, and itch—and think that the wound is getting more infected, so they put on even more Neosporin. This, of course, increases the allergic reaction,” she explains.
Tea tree oil
Tea tree oil is proof positive that even natural ingredients can pose problems and are common causes of skin irritation. While it does have antimicrobial effects and is considered an anti-inflammatory agent (and, as such, is found in all kinds of products for acne, eczema, and more), it’s also the most reported essential oil allergen, says Dr. Gmyrek. Most times, sensitization, allergy, or dermatitis is caused by application of the pure oil, she adds, noting that products with higher concentrations of the ingredient are more problematic. “Aged or oxidized tea tree oil is also more likely to cause a reaction, because the tea tree oil components break down to other compounds that have an even higher potential for allergy,” she explains. Choose tea tree oil products in packaging that minimizes exposure to light and air and discard any products that are starting to change color or smell, she suggests.
Lavender oil
Like tea tree oil, lavender oil is another common irritant in the “natural ingredients” category. While there are many types of lavender oil—found in everything from perfumes to household products to skin-care creams and soaps—they all contain a compound known as linalool; when this reacts with oxygen, it forms sensitizing chemicals known as hydroperoxides, explains Dr. Gmyrek. “There are numerous reports of lavender-induced allergic contact dermatitis in medical literature. For example, aromatherapeutic pillow sprays that contain the ingredient end up causing facial dermatitis,” she says. The irony here is that many people are using lavender oil because they’re trying to relax but ultimately end up creating another problem for themselves, she points out.
Propylene glycol
An extremely common ingredient found in a number of different cosmetic formulations, “this causes a multitude of reactions and irritations,” says Dr. Dhaval Bhanusali, a board-certified dermatologist in New York City. But unlike an acid or retinoid, it’s not necessarily irritating by nature. The problem? Many people have an actual allergy to it—so much so, in fact, that it’s previously been named American Contact Dermatitis Society’s Allergen of the Year—talk about a dubious distinction. Because it can function as everything from a humectant to a preservative to a solvent, it’s found in a dizzying array of personal care products, though Dr. Bhanusali notes that, in his experience, hair products, such as shampoos and hair dyes, with propylene glycol tend to be especially problematic, causing irritation along the scalp and hairline.
Formaldehyde releasers
Although formaldehyde is not usually found on cosmetic ingredient lists (although it does pop up in some nail products), formaldehyde releasers are commonly used as preservatives. “These are chemicals that will decompose over time, to form molecules of formaldehyde,” explains Dr. Gmyrek. “The estimated prevalence of dermatitis from formaldehyde is about 1.5% to 2.4%, but the issue is that sensitization can occur after repeated exposure,” she says. In other words, even if you’ve been using a product that contains one of these formaldehyde releasers for a long time with no issue, you can suddenly end up developing an allergy or reaction, seemingly out of the blue.
Common formaldehyde releasers to look for on ingredient labels include DMDM hydantoin, imidazolidinyl urea, diazolidinyl urea, methylene glycol, and quaternium 15, she says. A formaldehyde resin, toluene sulfonamide formaldehyde resin, often found in nail polishes, is also worth avoiding. It can cause signs of irritant contact dermatitis such as redness and swelling, not only on or under the nail but also on areas such as the lips and eyelids, which are exposed to the ingredient when you touch your face, cautions Dr. Gmyrek.
5 skin-care ingredients that work for almost all skin types
Now, for the good news. The five ingredients below tend to be very well-tolerated and are unlikely to cause any issues. While you can never say never, the doctors we spoke with suggest these as universal fail-safes. (And if you want to be extra cautious, you can always take any new products for a test run via a DIY patch test. Apply a small amount on your inner forearm and monitor your skin for things such as hives, redness, rashes, or any other signs of irritation for a few days before applying the product all over your face.)
Petroleum
While the ingredient gets a bit of a bad rap, Dr. Gmyrek says that opting for petroleum-based beauty products is a safe move: “The risk of any allergic or irritant reaction is incredibly low.” She goes on to say that petroleum-based products also don’t need preservatives. Petroleum can’t support the growth of bacteria or microorganisms—an added boon, given that many preservatives (such as parabens and methylisothiazolinone)often are, in and of themselves, the reason for skin irritation.
Try the cult-classic Vaseline Jelly ($1.79), which can be dabbed on pretty much any and every type of skin woe and is both dye- and fragrance-free. (Both are common irritants.)
Niacinamide
Dr. Bhanusali says this B vitamin is one of his favorite skin-calming ingredients, noting that he often pairs it with actives that are more common irritants, such as retinol or alpha hydroxy acids such as glycolic acid, for his patients with sensitive skin. Not only is it very soothing, but it also offers a wide array of benefits, including acting as an antioxidant, helping the skin retain moisture and combat dryness, and reducing both redness and hyperpigmentation. So if you can’t tolerate some of the more potent anti-aging ingredients out there, niacinamide may be a good alternative.
Find it in Paula’s Choice 10% Niacinamide Booster ($46), a serum that’s packed with the ingredient to help improve skin tone and texture in one fell swoop.
Pure aloe vera
There’s a good reason aloe is a go-to for sunburned skin. It has a low rate of both allergic and irritant reactions, has been shown to be anti-inflammatory, and is another option that helps with wound healing, says Dr. Gmyrek. It’s also a great hydrating ingredient, a boon if you have dry skin.
Just make sure you’re using a pure aloe vera gel, like Seven Minerals Organic Aloe Vera Gel ($18.95), rather than a product that combines it with other additive ingredients.
Castor oil
Another choice option, castor oil is so unlikely to cause irritation that it’s sometimes even used to manage eyelid blepharitis or inflammation, says Dr. Gmyrek. Plus it’s also antimicrobial, is anti-inflammatory, and has wound healing properties.
It’s the star ingredient in Dr. Rogers Restore Healing Balm ($30), a multitasking, moisturizing salve that can be used on everything from cuts to rashes to chapped lips.
Chamomile
While yes, there are many natural ingredients that can be problematic, chamomile is not one of them, hence why you’ll often see it in cosmetic products geared toward sensitive skin. “Chamomile is an antioxidant that’s anti-inflammatory and moisturizing and is well-known for calming the skin without being a source of irritations or allergies,” says Dr. Gmyrek. She says it’s often used in water-based skin-care products, such as cleansers, toners, serums, and more lightweight lotions; Summer Fridays Dream Oasis Deep Hydration Serum ($44) is one good example. The formula pairs chamomile along with several other potent skin soothers and redness reducers—colloidal oatmeal, aloe, and arnica—making this serum a good choice for those with sensitive skin, or even conditions such as eczema.
