· By Raja Mudad
Patch Testing 101: How to Try a New Active Safely
It's tempting to add a new product straight into your full routine the day it arrives. For most gentle products that's fine — but for anything with a strong active ingredient, a two-minute patch test first can save you a week of irritation.
Why Patch Test
A patch test checks how your skin reacts to a new product on a small, contained area before it's on your whole face. It's especially worth doing for actives like retinol, exfoliating acids, or vitamin C — and for anyone with sensitive or reactive skin.
How to Do It
- Apply a small amount to an inconspicuous spot — the inside of your forearm or behind your ear both work.
- Leave it alone for 24–48 hours. Don't apply other new products to that same area in the meantime.
- Check in at the 24-hour mark, then again at 48 hours — some reactions take a day or two to show up.
What Counts as a Reaction
Mild tingling on first application isn't unusual for some actives. Redness that spreads, persistent itching, burning, swelling, or small breakouts confined to the test area are signs to stop and not use the product on your face.
Especially Worth Doing For
Retinol, exfoliating acids, and any new vitamin C or brightening serum — particularly if you're introducing more than one new active around the same time. Curious about the right order to bring new products into your routine once they've passed a patch test? We covered that in In what order should I apply my skincare?