How to Patch Test Cosmetic Skincare

Apply a small amount of the new product to the inner forearm or behind the ear, twice a day for 24 to 48 hours. Observe for any redness, itching, stinging or rash. If your skin responds well, you can introduce the product to your face in a small amount and continue to watch your skin. If irritation appears at any stage, stop using the product. For severe, spreading or persistent reactions, seek medical advice. Patch testing isn't a substitute for medical care, but it's a thoughtful first step.