I use this in the morning because I always wake up puffy eyes. This helps the puffiness calm down rapidly. It's actually kind of amazing how fast it works. You only need a little product too, so this will last for ages. I'm not sure if it's doing anything for my dark circles though. I think for me is more of a health thing. I noticed they get better when I eat better and drink more water, and have yet to find a product that helps reduce them.
The only issue I've had with this is when I tried to layer my eye cream over it (currently using one from Acure), I got some milia under my eyes. I think using both products is too much for me. The milia went away when I only applied this serum and no eye cream. I only use my eye cream by itself at night now, since I don't care if I have puffy eyes while I sleep. I haven't had any issues with wearing this under makeup though! I wear two concealers for my dark circles, and they layer perfectly over this serum.
After spending much of my youth scrubbing my skin off with apricot scrubs, I'm never looking back after using chemical exfoliators. I've been using this for about a month now, and I feel confident in saying that this is a great acid for the price! Sometimes I get a tingly sensation when applying it, but it never burns in a painful way. It feels much more gentler than using a scrub.
I personally like using this in the morning, even though Deciem says to use it at night. I use my retinols at night and do not want to mix two harsh products at the same time! So far I haven't experienced any bad reactions from using it in the AM, but I make sure to slather on 1/4 tsp of sunscreen every morning. I also like to wear a hat when it's extremely sunny outside. Please be careful with sun exposure when using this! I also like using it before masks to help the product penetrate more.
I know some people have reported that this has dried out their skin. I naturally have dry skin, but this product hasn't made me drier. My skin does feel a bit tight right after applying it, but I make sure to use hydrating serums and moisturizer to help combat that tightness. If anything, my skin looks brighter and I've had less breakouts since I started using it.
Also the nozzle it comes with is brilliant! I love how much control it gives me when I'm applying product to a cotton pad. It never causes me to spill too much product.
Is it my favorite acid? Unfortunately no, Paula's Choice always has a special place in my heart. I find PC to be more smoothing and easier to apply. I personally haven't used Pixi's glow tonic before, so I can't compare, but this product is pretty darn good. I can't believe the value for the amount of product you get. This is one best affordable acid I have tried and recommend it to anyone who is new to acids!