I have been using The Ordinary Retinal 0.2% Emulsion for about a month now, bought from Ladily. Since I was already using lower-strength retinol previously, my skin tolerated this 0.2% concentration well. It is very potent. I noticed a visible difference in the texture of my forehead lines and some stubborn dark spots after just a few weeks. It definitely helps with skin firmness and luminosity. However, a small limitation: this is strong stuff. Even for someone experienced, I would suggest starting slow to avoid irritation. My skin felt a bit dry the first few days, so pair it with a good moisturizer. The 15ml bottle is small, but because you only need a drop or two, it lasts a decent amount of time. If you are looking for advanced age support and smoothing, this is a top-tier retinoid serum. Just make sure your skin is ready for this strength before buying.