This serum was my least favourite of the three, but I didn't hate it - by no means! I'm not even sure why it was my least favourite - the results it yielded were quite good.

I love the dropper you use to apply the product - it allows for control so you don't use too much. I did find that the lack of directions on the product was a bit confusing though. I didn't know how much (or little) to apply, so I kind of just did my own thing.

My skin tone has definitely improved, I feel. I still have the dark circles under my eyes - I think I always will, but I felt like the rest of my skin tone evened out. The natural progression of discolouration on the side of nose and my laugh lines/cheeks seems to have lightened with use of Kiehl's Dermatologist Solutions Clearly Corrective Dark Spot Solution. I think I might keep on using it after all.