COSRX - The Vitamin C 13 Serum

Love this serum! It absorbs quickly, brightens my skin, and helps even out my tone without irritation. My face looks more radiant and hydrated after just a few weeks. Definitely a new skincare favorite!

I wasn't going to review this for a while bc I just got it. However, I had to comment on how well it's packaged. Specifically the bottles seal. My husband was with me when I twisted it open & made the audible "wtf". It sounded like I was opening a fresh, tiny soda😂 I'm guessing since the vitamin C is pure it's causing a release of gases when opened. I've used countless serums in little glass bottles over the yrs, including vita c. From $10 up to $150 in price. Not ever has a product been so well sealed. And that's actually the most important part of skincare packaging. I'm impressed. I can say already that I like the way the serum feels. You think it's going to be an oil when you're dripping it on & applying it. Then it starts feeling like a cooling water. As it dries down it gets a little tacky. Once I put moisturizer over it the tackiness went away. And I can report that the bottle continues to make the spphh sound every time you open it. So, it has a 10/10 in packaging, imo.

Amei

Smells funny, but vitamin c Smells strong...Let's see

I am on my second, ordering a 3rd. My skin loves this stuff. I use it weekly in summer and biweekly in the winter months. I used to fall victim to the super expensive medspa serums, cleansers and moisturizers. Not since discovering the COSRX snail mucin line. I am in my early forties and all of a sudden, I find myself trying to take care of my skin even more than years before. This line works and cost effective.

It's difficult for me to open the box yet worth the fight. I love the sound upon opening. The suction says it's well packaged. It's a fantastic product. I noticed while starting on the second bottle an improvement in my skins appearance. I had have discoloration but my skin is much more even toned now. This is a pleasant surprise. No C serum improved my skin. I use vitamin C serum because you're "supposed" to. This one works. This product even teaches users how to apply and massage the serum in. I'll continue to buy the COSRX serum because it works. It lasts about a month using once daily. For the price that's good enough considering less effective vitamin C serums show no improvement at all. I love that users are taught to refrigerate this C Serum. That means top notch quality! The last picture is the difference the loss of potency when the product is not refrigerated . The final picture is the serum when it's fresh and refrigerated. The serum is lighter in color when it's kept cold and fresh

I was looking for a good vitamin C serum that is also not on the pricey side and decided to try this popular one out. The product definitely smells very fishy when you first try it and that put me off at first. I couldn’t bear the lingering smell so I gave my first bottle away to a friend. I ordered it again for my mother who does not mind the smell as much and put it in the fridge for her. After about a week in the fridge, I noticed that the smell was not that bad anymore. Two weeks later, it was completely gone!!So I ended up purchasing this 5 more times (for myself and others). Bottom line is, don’t let the fishy smell deter you from purchasing this item!

Ok

Really lovely, good for evening dark spots and creating a glow. You have to keep it in the fridge and it does stink. If your skin can tolerate it, I’d definitely go up to 23%. Best to use at night, as it does react with moisturiser (not in a painful way), meaning you can get orange tide marks.

Nice product.. Looks good on face

The COSRX Pure Vitamin C 23% Serum has quickly become one of my favorite brightening serums. It’s strong enough to make a visible difference in dullness, uneven skin tone, and fine lines, yet the formula feels balanced thanks to the addition of vitamin E and hyaluronic acid.I noticed my skin looking fresher and more radiant within a few weeks, and with consistent use, my complexion feels smoother and more even. The texture is lightweight, absorbs well, and doesn’t leave a heavy or sticky finish.If you’re looking for a powerful yet hydrating Vitamin C serum, this one really delivers. Just remember, like with all skincare, patience and consistency are key to seeing lasting results.

I love the this 😍.

Very good product

This is my 4th bottle and the most gentle vitamin C serum I have ever use. Suitable for sensitive skin. Noticeable effect after using second bottle.

Light weight and absorbs nicely

Lovely product

really loved this! felt like it really started to help with my hyperpigmentation

Ok

Love this Vitamin C! I haven’t seen much of a difference with skin glow but it’s a great option

Amazing quality skin care item for a very affordable price point. Brightens and clears skin from early signs of aging.

really good

I'm on my 3rd bottle and all I can say is WOW. I can really tell the difference in my skin. I love the entire cosrx line

I’d like you to meet officially my glow dealer. I put her on, and it’s like someone turned the brightness up on my face without making me look oily or fake — just pure, radiant, even skin.She’s lightweight, sinks in instantly, and doesn’t give me the dreaded sticky or stingy drama that so many vitamin C serums bring to the table. Within weeks, my dullness is GONE & my redness? Fading. My entire complexion? Smooth, even, and practically sparkling. I look like I’ve been sleeping eight hours and drinking green juice (spoiler: I haven’t).This isn’t just brightening — it’s transformative. My morning routine feels incomplete without her, and when I skip a day, I can tell. She’s will forever live in my mini fridge rent free.She’s the reason I’m glowing like I actually have my life together.

My face lightened especially my dark spots.

Ive been using this serum for a few months now. I was struggling with dull looking skin and this has helped brighten my skin. It looks smoother too!

It works wonders on my hyperpigmentation without an efty price

13% KEPT A HALF CUT APPLE FRESH AS LONG AS THE 23% DID, PLUS IT WAS FAR GENTLER ON THE SKIN.GUESSING THE 23% WOULD BE BETTER FOR HELPING MEDICATE A PESKY SKIN PROBLEM.

Newly started using it in my routineIt’s okay …haven’t used it for long yet

My favorite vitamin c it makes my face look 👀 beautiful and soft thank you.