Pick a small area of intact skin
The American Academy of Dermatology suggests using a small area such as the underside of your arm. Use the product as directed, including rinsing it off when appropriate. For ordinary skincare products, they suggest repeating the test twice daily for seven to ten days.
Watch for a reaction
If you develop itching, swelling or redness, wash the product off and stop using it. Ask a healthcare professional for advice if the reaction is severe or persists. A home test cannot rule out all reactions or diagnose an allergy.
Change one product at a time
Keeping the rest of your routine stable makes it easier to identify a trigger. If you have just had a peel or microneedling, follow your personal aftercare and ask when it is appropriate to start new products.