How many new products can I introduce at once?

Introduce one new product at a time and leave the rest of your routine unchanged while you test it. More products increase the chance of side effects, and identifying which ingredient caused irritation can be difficult when several things change together. A short routine is less glamorous than a counter full of bottles, but it is easier to keep track of.12

How do I introduce new products into my skincare routine?

  1. 1Choose a quarter sized spot, such as the underside of your arm or the bend of your elbow, where the product will not be rubbed or washed away.
  2. 2Apply the normal amount and thickness twice daily for seven to 10 days, as though you were using the product regularly.
  3. 3Leave the product on your skin for as long as you normally would. For a cleanser, keep it on for five minutes or follow its instructions.
  4. 4If no reaction appears after seven to 10 days, add the product to your routine. If a reaction appears, do not add it.
1

Retinol and glycolic acid can cause temporary irritation, especially on sensitive skin. Testing helps you notice a reaction before using a new product across a larger area.1

How long does it take to know if a skincare product works?

The seven to 10 day test is for checking whether your skin reacts, not for measuring improvement. A clear test spot does not tell you how long a product will take to improve the concern you are using it for.1

What should I do if my skin reacts?

A reaction can make skin red, itchy or swollen. Gently wash the product off as soon as possible and do not use it again. Make an appointment with a dermatologist if irritation or contact dermatitis appears; seek help if a reaction is severe or not relieved by a cool compress or petroleum jelly.12

Should I follow the product's directions?

Read and follow the product's use instructions during the test, especially for how long to leave it on. The directions are not the glamorous part of a new bottle, but they beat improvising.3

Where this answer comes from

  1. 1How to test skin care productsaad.org
  2. 2The Correct Order for Skin Care Productshealth.clevelandclinic.org
  3. 3Consumer products: cosmeticsgov.uk