How to test a new skincare product

This page goes with Card 2 of your Glass Skin Blueprint. If your skin is sensitive or reactive, testing a new product on a small area before using it on your whole face is a sensible way to start. It takes a little patience.

Testing can help you spot a possible reaction before you use the product across your face, but it can't guarantee how your skin will respond. Keep an eye on how your skin feels over the first few weeks, even if a test went well.

Testing one new product

This is the method the American Academy of Dermatology recommends:

1. Pick a small spot on the inside of your arm or the bend of your elbow, somewhere it won't be rubbed or washed off straight away.
2. Apply the product to an area about 2.5 cm across, roughly the size of a 10p coin. Use the amount you'd normally use on your face.
3. Do this twice a day, morning and evening.
4. Keep going for 7 to 10 days.

For products you rinse off, like a cleansing oil or cleanser, leave it on for about 5 minutes, or for as long as the product instructions say, then rinse it off.

What to look out for

Redness, itching or swelling on the test spot, or burning or stinging that doesn't settle.

If you notice a reaction

Gently wash the product off as soon as you can and don't use it again. Then email me, so we can work out what to do next.

If the reaction is severe, getting rapidly worse, oozing or increasingly painful, or you feel unwell, hot, cold or shivery, get medical advice straight away: call 111 or use 111 online.

If your lips, mouth, throat or tongue suddenly swell, or you're struggling to breathe, call 999. Card 5 in your Blueprint has the full list of signs to act on straight away.

If your skin stays calm

You can start using the product on your face. For the serum, follow the plan on your cards and introduce it slowly: if your skin is sensitive or reactive, stay on 2 evenings a week until your skin is comfortable, then increase gradually.

When you have several new products, like your Blueprint

What the evidence covers. The dermatology advice above is written for testing one product. We haven't found guidance that says whether to test several products at the same time or one after another, so there is no proven method for testing a whole routine.

What I suggest. This is K Skin Aura's practical suggestion, not a medical protocol:

• If your skin is sensitive or reactive, test each new product using the method above before using it on your whole face.
• If you're testing one at a time, start with the serum. It's the most active product in your set.
• How you fit the tests around starting your routine is up to you. If you'd like help planning your first weeks, email me.

What Anua says about this serum

Anua's own guidance for the Niacinamide 10 TXA 4 Serum says very sensitive skin should start with a patch test, applied behind the ear or along the jaw for 24 hours before using it across the face, and should use it less often at first.

Anua's 24-hour guidance is specific to this serum. The dermatologist method above is general guidance for testing skincare products. Whichever approach you use for the serum, introduce it slowly using the plan on your cards.

If you react to skincare often

This home test isn't the same as clinical patch testing. That's a test a dermatologist uses to find out what you're allergic to, using tiny amounts of known allergens placed on your skin under patches and checked over several days. If you keep reacting to skincare or can't work out what's causing it, speak to your GP. They can advise whether further assessment or referral is appropriate.

Still not sure?

Email me at admin@kskinaura.co.uk. I'd rather you ask than guess.

Mari x

Sources: American Academy of Dermatology, how to test skin care products; Anua guidance on its Niacinamide 10 TXA 4 Serum; NHS, contact dermatitis. This page is general skincare information and is not medical advice. If you are pregnant, breastfeeding, using prescription skincare or managing a skin condition, check with a healthcare professional before use.