I spent 6 months using a $12 hyaluronic acid from Amazon and wondered why my skin was still dry. A $38 one from a proper derm brand fixed it in 2 weeks - anyone else find the price gap actually matters for actives?
Oh man, same thing happened to me with a vitamin C serum! I was using this $15 one from a drugstore brand for like 4 months and saw zero results. Then I switched to a $45 one from a skincare line my derm recommended and within a week my dark spots started fading. It's wild because you think they must be basically the same ingredients but they really aren't. The cheap stuff just doesn't have the right formulation to actually get the good stuff into your skin. I learned that lesson the hard way too, now I spend a bit more on my actives and save on the basics like cleanser.