I'm very very close to giving this product 5 stars. This is of course one of the most popular and hyped brightening serums so I had to try it. So far it seems to be great. I've been using 2 drops a day, everyday, right after using my hydrating toner. I love the consistency and it doesn't feel irritating on my sensitive dry-combo skin. Brightening products like this do take time to show results however so I can't say it's done much in that regard considering I've only been using it for a week or so but as far as brightening serums go, it seems to be the best I've used so far. Only thing holding me back from a full 5 star review is that it's only 30 ml, which is a bit small for how much it costs full price so I def recommend picking this up if it's on sale like I did. However I noticed that even 2 small drops was more than enough to cover my whole face so it definitely goes a long way.