While you might assume that there are a few random ingredients in skincare products that might cause an occasional negative reaction, the American Academy of Dermatology (AAD) points out that there are actually over 15,000 substances that could be potentially reactive problems when all it alone. Um, yikes!

Fortunately, performing a patch test can help you figure out if any of these ingredients are something you need to stay away from as much as possible to avoid potential pain and damage to your skin. A patch test is simply using a small amount of a product on your skin and keeping an eye on how your body reacts, according to Medical News Today. If you don’t have a bad reaction, then everything might be fine and dandy, and you may have found your new favorite product. If you’ re concerned that you might have a delayed or gradual reaction, then you can keep your patch testing going over the course of a few days to see if any issues develop.

Although a patch test is something that a dermatologist can do for you, you can also easily do a patch test in the comfort of your own home. However, be sure to perform it properly and safely so you can truly rely on the results.