A patch test means trying a new product on a small area before applying it to the whole face. This simple step helps you observe how skin reacts in advance and is especially useful for sensitivity-prone skin.
Apply a small amount to an inconspicuous area (inner elbow or under the jaw). Observe for 24–48 hours. If no notable redness, itching, burning or discomfort appears, gradually adding it to the routine is generally safer.
Introducing new products one at a time follows the same logic: starting several at once makes it hard to identify the cause of any reaction. Consult a dermatologist if unsure about product selection and testing.