How to Patch-Test a New Skincare Product

The prettiest ingredient list cannot tell you exactly how your skin will respond. Before adding a new face oil, butter or scented product to your routine, give it a small introduction.

The small-area test

The American Academy of Dermatology suggests applying the product to a quarter-sized spot on the underside of the arm or inside the elbow twice daily for 7–10 days. Use it as directed: leave a leave-on product on, and rinse a wash-off product according to its directions. Choose a spot that will not be rubbed or repeatedly washed.

Watch for itching, redness, swelling or another uncomfortable change. If a reaction develops, wash the product off gently and stop using it. A severe or persistent reaction deserves medical attention. If you have a history of significant allergy, get advice from a qualified clinician before trying a suspect ingredient.

What the test can and cannot tell you

An uneventful small-area test makes wider use more reasonable; it cannot guarantee you will never react, especially if you later use more product or combine it with other ingredients. Test the finished product rather than assuming each ingredient predicts the full blend. Introduce one new item at a time when possible.

An at-home use test is also different from diagnostic patch testing performed by a dermatologist to investigate contact allergies. If reactions keep happening, ask a dermatologist about that evaluation.

A slow start is a kind way to care for the skin you have today.