Wash and dry a small area of skin, usually behind the ear or along the jawline
Apply a small amount of the product to the area
Leave it on for the same amount of time you would normally use it, or follow the product instructions
Do not wash the area unless the product instructions say to
Check the area after 24 hours
Check again after 48 hours
Watch for redness, itching, burning, swelling, rash, or bumps
If any reaction appears, stop using the product
If no reaction appears, use the product on your face as directed
Test one product at a time