TIAM My Signature C Source, Vitamin C Serum, Pure Vitamin C 20%, Ascorbic Acid, 1.0 fl oz

This is the best Vitamin C serum I have ever used (and I have used many...from the most expensive brands to homemade and in between). It's 20% vitamin C and the pH level is low enough to work as an exfoliant. Most Vitamin C serums I've tried had a ph level that was too high rendering it ineffective, but this is the perfect ph level to work and work very well. It quickly lightens PIH marks and evens and brightens skin tone.The best way to use this product is at night because sunlight will break it down. I do use it at night and also during the day when I am not going to be outside at all or exposed to sunlight. I wash my face and then apply the serum and wait 30 minutes before continuing with my skincare routine. Waiting 30 minutes is very important because that is how long it takes for the Vitamin C (same thing with any BHA or AHA product) to work, after 30 minutes it has already naturally neutralized itself. I keep this serum in the box and keep it refrigerated to keep it from oxidizing quickly. It's best to use the bottle within 3 months. If it turns a dark orange color, it has oxidized and should be thrown away.I am thrilled with the results of this product and will definitely continue using this to keep my skin tone even and bright. Love this serum!

It’s empty

As someone who was looking to improve my skin tone, I am really glad that I bought this. I've basically used up my whole bottle currently, and I have been using it for several months with a break, only because my skin was very irritated already when I first bought it. When I first got it, my skin was already very irritated, and it wasn't a good idea to use this on top of it, because using too many harsh products is not good. It can sting if you have open wounds/pimples or if your skin is very sensitive. You should get your skin used to it little by little. That said, after my skin recovered, which took a month or two, I was very careful not to over stimulate my skin. And focused on allowing the serum to work on its own without any other products getting in the way. So, after I use toner, I put this on my cheeks, around my temples, and chin, because it can dry out and redden the area around my nose a little. But, mostly, it is due to the reason that I only use it around the areas where I have dark marks. It fades the marks very quickly, and I notice that it helps pimples that I do have heal quicker. I noticed after several weeks of using it diligently, my face is definitely a lot brighter. It is helpful; I also used it in conjunction with twice a week exfoliation. I have quite oily skin, so for me, I like to exfoliate a lot. After I put it on, I wait 10-15 minutes for it soak in, it's kind of sticky at first, so I just after the wait, the stickiness usually subsides. Then, I put on a light moisturizer. Overall, I really recommend it if you want to fade acne marks.

If you are a skincare junkie like me, you know how hard it is to get a decent active at this price point. Ost C20 is a fantastic vit C serum that worked really well on my sensitive skin. I did not keep my bottle in the fridge, but I did keep it in a cool place away from sunlight. It took a good 6 months before I deemed it too oxidized to safely use and threw it out. It probably helps that I only purchase this item in the Winter time to avoid having it exposed to high temps during delivery and whatnot. Someone has mentioned that the bottle leaks if you leave it on its side, and I find that to be annoyingly true. My only two quibbles with the product itself are that 1) the long lasting metallic smell, and 2) how sticky it is. There is a newer version, the C21.5, which I hear is an improved, stronger version. That may be my next purchase.

I was about to return this product if the color of the serum is orange or dark because I have been buying this product before so I know the color would be clear if it’s good… and it was good, so I’m keeping it. I’ve used this for years and it’s really good. Still love this product.Update: it starts leaving a white cast which is weird.

This has made my skin brighter, helped a zit heal faster, and overall I feel like my skin is more glow-y. A little exfoliating. Some redness upon application, but that goes away (for me) within a few minutes.Some notes about the product and application:Use a little bit (2-4 drops max). It's slightly sticky but overall pretty spreadable product. You only need a thin layer on your skin. If you use more than a thin layer you may notice some irritation. I experience some VERY mild irritation that quickly disappears upon applying 3 drops and spreading the serum in a thin layer on my skin. Initially, I made the mistake of using more and experienced a nasty stinging/burning sensation (I will say the next day my skin had a crazy glow to it though). The principle of "less is more" definitely applies here. And you can always apply more but start small see what your skin tolerates.Keep your bottle in a dark, dry place that is preferably cold. Vitamin C becomes less effective with exposure to sunlight, humidity and high levels of heat. Definitely something to keep in your bathroom if it is very well ventiltated.My skin concerns:- dry- acne along jaw line- prone to redness- eyes sensitive to fragrance

Discovering the TIAM My Signature C Source Vitamin C Serum has been a skincare revelation. This serum is a smooth delight on the skin, leaving it feeling velvety without any overpowering scent. The magic lies in its transformative effect – my skin appears brighter and firmer from the very first use. It's become a must-have for a radiant and healthy complexion. In short, TIAM My Signature C Source Vitamin C Serum is skincare simplicity with extraordinary results!

Its too much work and its weird. You have to store it in the fridge and then when you apply it nightly it stings like crazy, feels uncomfortable. It leaves your skin feeling dry and it just enhanced dry patches on my face. Didn't lighten at all. Total waste of money.