Sometimes. Retinol can be irritating, especially to sensitive skin, and also if the product is highly concentrated. Common side-effects can include itchiness, redness, dryness, scaly patches, and peeling. Rarer side effects are acne or eczema flare-ups, skin discoloration, and a burning or stinging sensation after application. You’re more likely to experience these side effects if you’re a novice retinol user. If you’ve never used retinol before, it’s better to start off with a low-concentration product and work your way up from there. Also remember to do a patch test on every new product you use before putting it all over your face.