Before you apply a new product to your whole face, test it on a small patch of skin. It takes a minute and can save you from a bad reaction. This guide shows how to do it and what to look for.
Key takeaways
- Test on your inner forearm or behind the ear.
- Wait at least 24 to 48 hours before using the product on your face.
- Stop immediately if you see redness, itching or swelling.
How to patch test
Wash and dry the area, apply a small amount of the product, and leave it uncovered. Check after a few hours and again after 24 to 48 hours. Some reactions take longer, so repeat for several days if your skin is very sensitive.
What counts as a reaction
Redness, itching, burning, bumps or swelling are all signs to stop. Mild tingling can be normal with active ingredients, but ongoing discomfort is not.
Who should patch test
Everyone benefits, especially those with sensitive skin, eczema, a history of allergies, or when trying a product with actives such as vitamin C or niacinamide.
Where to buy: our recommendations on Amazon
These picks link to Amazon so you can check current prices, sizes and customer reviews. As an Amazon Associate we earn from qualifying purchases, at no extra cost to you.
Our top pick: The Ordinary Niacinamide 10% + Zinc 1% Serum
A popular active serum that is worth patch testing before full-face use.
The Ordinary
Niacinamide 10% + Zinc 1% Serum
A budget-friendly serum made for blemish-prone, uneven-looking skin.
Check price on Amazon Details and FAQAlso consider: Dr.Althea 345 Relief Cream
A calming cream that is still worth patch testing if your skin is reactive.
Dr.Althea
345 Relief Cream
A lightweight cream with PDRN, hyaluronic acid, centella and niacinamide for post-blemish care.
Check price on Amazon Details and FAQFrequently asked questions
How long should I wait after a patch test?
At least 24 hours, and up to 48 hours or more for reactive skin.
Does a passed patch test guarantee no reaction?
No. It lowers the risk but cannot rule out later sensitivity.
What should I do if I react?
Wash the product off, apply a plain moisturizer, and talk to a pharmacist or doctor if symptoms are strong.
This article is for general information and is not medical advice. Product details and prices can change, so check the Amazon listing before you buy.