How to Patch Test a New Skincare Product and Why It’s Important

November 16, 2022
Jordan Julian
By: Jordan Julian | by L'Oréal
Person's forearm with a swatch of white product on it

We are firm believers that few things are as exciting as trying out a new skincare product, be it a cleanser, moisturizer or exfoliator. That said, it can also be slightly nerve-wracking to shake up your tried-and-true skincare routine with something new. Who wants to risk unwanted breakouts? More importantly, though, there’s always the chance that trying out a new product may even cause a rash or an allergic reaction.  

Luckily, there are steps you can take to try to reduce the likelihood of unwanted reactions when trying out a new skincare product. We tapped board-certified dermatologist and consultant Dr. Lisa Nyanda-Manalo to break down what you need to know about patch testing, a method of testing skincare products before you slather them onto your skin.

What Does It Mean to Patch Test Skincare Products?

“Patch testing for skincare products means to determine if a rash is caused by an allergy to a particular chemical or ingredient when it comes into contact with the skin,” explains Dr. Nyanda. It consists of applying a small amount of a product to an area of your skin and waiting several days to see if your skin has some sort of reaction. According to Dr. Nyanda, if your skin becomes red, itchy or raised in the test area, that could indicate an allergic response to an ingredient in the product. 

How Do You Patch Test a Skincare Product?

Your dermatologist may offer patch testing in their office, but you can also do your own patch test at home in a few steps. Be warned: You’ll need to be patient while you wait to see if your skin reacts. 

First, apply the product in a small, quarter-sized patch on your skin. Dr. Nyanda recommends the inside of the arm, “because it is not likely to be scratched off or manipulated once it is applied.” Then, follow the instructions for how long you would normally leave on the product.

“A skin reaction may not develop immediately, so it is recommended that you repeat the patch testing twice a day for up to seven days,” says Dr. Nyanda. “If a reaction is observed, the area should be cleansed immediately with cool water." If no reaction is observed after about seven days, the chances of a skin reaction are likely low.

Why Should You Patch Test Skincare Products?

Though it may seem excessive to test a product for a week before fully taking the plunge and incorporating it into your skincare routine, patch testing is an important precaution. 

As Dr. Nyanda explains, patch testing skincare products helps evaluate for possible sensitivities, including allergic skin reactions, related to skincare products. If you’re someone who suffers from regular rashes or itchy skin, this is one way you can try to figure out which products and ingredients work for your skin — and more importantly, which to avoid.     


Photo: Chaunte Vaughn

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