I had previously tried retinol from a well-known company and I had absolutely no problem, on the contrary, I really liked it and I decided to try to incorporate it into my routine. I ended up choosing this one because it was more affordable than others, but the result completely disappointed me. It feels very heavy, it is clearly oil and not serum, it never absorbs (even if I use a minimal amount), and the smell is like old frying oil. I only give it 2 stars just because I don't have an opinion on its effectiveness. But with such a feeling, I probably won't learn anything either.