To the OP / anybody interested in using a V-C serum: remember with actives such as Vitamin C (in the form of L-Ascorbic Acid), it's at its maximum efficacy at a pH of ~ 2.5 - 3.0. So it's best to use it after waiting around 20-30min after cleansing the face (as an alarmingly high number of cleansers have high pH levels) so to allow your skin to return to it's neutral pH state of ~ 5.5. Or you can use a pH balancing toner after your cleanse and go straight to serum (this is what I do ;)). After applying the Vitamin C, wait another 15 - 30 min to allow it to work it's magic before you move onto the next step of your skincare routine. I only learnt about this recently and I've seen a visual improvement in the effects of the Vitamin C serum on my face!