I mainly ordered this because I wanted to get rid of the PIH I got after a massive breakout (I don't know the reason though, that was a first!). So, this is my first Vit C serum ever and I'm liking it so far. It did ligthen the PIH a bit (2 months of using it), the breakout area became less noticeable! It's the 3rd month and still have more  than half of the bottle. I keep it refregerated (in its package) so the colour remained the same as when it arrived. Some people may have a burning sensation for a few seconds? (I get it some areas sometimes but i can tolerate it).

Now about the customer service: Thank you Jolse/Bae :) It arrived quickly and I received a lot of samples, so nice!!!