I used this serum twice before without pairing it with the face wash or toner from the same line and it works well! If you use it consistently for several weeks in a row, you'll notice a significant difference in your overall skin texture. The only reason why I took off 1 star is because it feels too greasy for me to wear during the daytime (with or without makeup). So I end up using this only at night time. This brand came out with a new lighter version of this serum which I haven't tried yet but hopefully, it would solve that greasy feel. Also, if you haven't used this product before, it's best to shake the bottle really well before you take the dropper out to apply the serum to your face. The active ingredients inside the bottle separates when not in use.