I’ve tried tretinoin combined with hyaluronic acid and niacinamide, but I’ve also seen formulations that include hydroquinone ... or purple-brown marks left over from acne), tretinoin can ...

If you are a skincare enthusiast, you would know of tretinoin as a game changer for acne. Tretinoin is a Vitamin A derivative and a type of retinoid that is primarily advised to treat acne.