How should you test for allergies before using a new hair dye?

Performing a patch test is the best way to check for allergies before applying a new hair dye. This involves applying a small amount of the dye mixture to a discreet area of the skin, usually behind the ear or on the inside of the elbow, and waiting 24 to 48 hours to observe any reactions. This test helps identify potential allergic reactions to ingredients in the dye, minimizing the risk of severe allergic responses when the dye is applied more broadly on the hair.

While a sensitivity test might seem similar, it's essential to note that a patch test specifically focuses on skin reactions to the product. Testing temperature is irrelevant to allergy testing, as it does not provide any information about a person's allergic sensitivities. Checking skin tone, while important for determining the most flattering hair color, does not relate to allergy testing. Therefore, performing a patch test is the most reliable method for ensuring safety before dyeing hair.