First of all, this vitamin C serum is great value for the concentration. It worked as well as the Ordinary 23% vitamin C suspension tube except it absorbed faster and was better to use under makeup (because it didn’t leave my skin greasy). It certainly brightened my skin and helped my acne scars fade faster.

However, there are a few cons that stopped me from buying it again:
1. It’s not a very stable form of vitamin C, so it oxidized much faster than my other vitamin C serums. I think the oversea shipping process must contributed to this as well (unless the bottle I received wasn’t a fresh batch) because when I opened the bottle after it was delivered, the solution has a pale yellow tint to it and there were plenty of air bubbles.
2. It some times dried down to a white cast and felt a bit tacky so I had to carefully moisturized my skin before putting on makeup.
3. It broke me out after it started to oxidize so I had to stop using the serum when it was half full. This made me reconsider its value again.

So while I liked the results and the price, I wouldn’t buy this again because I prefer my vitamin C serums to be more stable.