Review (4/5): Great product!  A nice boost to your moisturizing routine
I received Dr. Au's face oil serum about 2 weeks ago and have been using it about every other day since I got it. Although it's a small bottle, you can tell by the look and feel of the serum that it is high quality and you really only need a few drops with each application. Since I started using it, there is a noticeable difference in my skin tone and it looks a lot more even. I have a lot of acne scars and they are already starting to fade significantly even though I don't apply the serum every day. I was worried that since it's an oil-based serum, I thought it would leave my face way too oily and thought it might make me break out more, but it really doesn't make you feel like you just slathered oil on your face. I have less breakouts, too.
The first few times I used it, I used about 7 drops to cover my entire face and neck (although you could probably use a little less). Although it's not extremely oily, it still leaves your face feeling like there's still a little something on it, so I started adding a few drops (maybe 4) in with my regular moisturizer and I'm in love, no oily residue in sight.
The oil itself is a little shimmery and needs to be shaken up a bit between each use. It comes with a little dropper built-in to the cap so you can add as little or as much as you want. It has a faint smell of vanilla, but it's just a touch, not overpowering at all. I can't smell it after application.
Overall, great product! Definitely will buy again and would recommend to add into your moisturizing routine. Would probably be good with an overnight face mask, too, although I haven't tried it yet. I couldn't give 5 stars because I really haven't been using the product long enough to see the full results. Perhaps I'll update my review after using the product more.