It's been a good four almost five months since I first started using the OST C21.5 vitamin c serum. I've been using this diligently every day for the past three months, so I'm more confident sharing my thoughts on this serum. Prior to that, I was using this every other day or less. The serum did not oxidise or even turn champagne coloured before I finished with it, which I take as a small victory. Unfortunately, that's the only visible success I can share regarding this serum. I've heard so many awesome things about this in terms of brightening, healing pigmentation, and fading sun spots and pimple scars that I kind of expected it to work magic on my skin. After a month of seeing no visible changes, i upped the usage from every other day to every day. Two months later, I was still hopeful, thinking it would take time. Now, almost at the end of three months of diligent, everyday usage, my skin is still the same as it was before, plus a few more pimple scars as a giant F you to my face and hopes of this working. Still, with skin, it's always different and it being effective for everybody didn't necessarily meant it would work on me. It didn't help with anything it said it would, to be honest, which is really disheartening. Maybe it's quietly doing its anti-aging magic on my skin but I can't see it? Regardless, I've since purchased a vitamin c replacement for this! For more read it here: http://malaysianbeautyhaul.blogspot.my/2016/09/review-ost-c20-pure-vitamin-c215.html Or follow me on insta here: https://www.instagram.com/peachy_amy/