C Tetra Advanced.

"This definitely has been an absolute holy grail for me and one that I recommend time and time again. It isn't the cheapest, but it is definitely the most advanced when it comes to not only giving you that instant boost of radiance and luminosity, but also delivering that long-term glow up. It uses that vitamin C derivative, which is super gentle to really help fade hyperpigmentation, achieve a more even skin tone, and get your glow game on point. But somehow this just gives you the nicest subtle glow from the instant you use it. Not only are we paying for those long-term gains, we're also getting some quick wins, too. On first use, you'll look in the mirror and think, 'Yeah, my skin just has a little bit of a dewiness, a little bit of a glow to it.' It's very natural. It's very subtle, but it's definitely noticeable. I'm already on bottle maybe three of it. It's quickly becoming a holy grail for me and great if you want a very subtle boost to luminosity."

"The vitamin C I'm reaching for is the Medik8 C Tetra Advanced. Very well loved, very well used, I'm getting to the last of this, but I'm determined to get the last bit out because I paid good money for this and I want to get my money's worth. This is great, it glows you to the gods. It's not super sensitizing and it definitely works to minimize any hyperpigmentation, get your glow game on point, and it is just beautiful. One of my favorite vitamin C's. It's also not super expensive. I like that Medik8 one because it's got some other beneficial actives for brightening the skin."

"One of my favorites is Medik8 C Tetra Advanced. I, as you can see from the state of this, I love this product. Works so well alongside tretinoin alongside retinol. It's amazing. It's my personal favorite, but it's not the cheapest out there."

"This is actually a potent vitamin C derivative. So, if you're somebody that's really sensitive to vitamin C, this will work. If you have very sensitive skin, this will work. I don't think I've achieved a glow up from a vitamin C like this one. It goes on beautifully. It doesn't have that offensive hot dog water scent that a lot of vitamin C's do, which obviously is a big tick in the box. And it just works. I think it proved to the world that vitamin C derivatives can deliver just as well, if not better, than pure form ascorbic acid. It performs in excess of any other vitamin C I've used. It's not the cheapest product out there. However, I find a little goes a long way. For the glow up it gives me and for the evening out of my skin tone, my hyperpigmentation, this is like a ride or die for sure."

"This is one of my favorite products from my favorite brand. If you want glow and you want a vitamin C derivative that actually packs a punch, this one absolutely love it. This banon is the glowiest vitamin C you will ever ever use. You will be blinding people with your radiance after just a couple of uses."

"This only launched in 2025, and the brand describes it as an instant illuminating vitamin C that gives you that quick fix glow up, but in the long term delivers an even skin tone and can help firm and increase elasticity in the skin. I was sold. Literally the second I read that, I applied it and thought, 'Wow, this actually lives up to the claims.' If you use your vitamin C for radiance, for luminosity, and for a glow up, this is the one that you should be reaching for. If you're using a vitamin C primarily for hyperpigmentation, dark spots, and uneven skin tone, you might want to stick to a pure form ascorbic acid. But Medik8 have proven this year that you can do vitamin C derivatives that actually work, that pack a punch, that deliver in a super gentle way, but still give you that radiance and luminosity we crave. This is really quite potent, but it's not sensitizing on the skin because it uses a vitamin C derivative. It's so well formulated. If you're looking for the ultimate glow up in 2026, this product is kind of all you need. It's that good."

"The C Tetra Advanced is the best vitamin C derivative on skincare planet earth. This gives you that beautiful glow, that lit from within radiance that I haven't actually got from any other vitamin C serum. If you're using your vitamin C just for the glow game, that radiance boost for that luminosity, this is the one you need to reach for. It's stunning. You'll get that glow after just two uses and the formulation is divine. This is actually the most potent vitamin C derivative that you're going to find. So if your skin can't tolerate pure form vitamin C, but you still want the results, go for this derivative. Super gentle, won't stress the skin out, but hands down the most potent one you're going to find. This is A+."

"This is the product that really got me into advanced vitamin C's. It just works so so well. It uses a 20% concentration of a high potency vitamin C derivative. Derivative forms of vitamin C are super gentle, but they're also really really effective. Studies show that it rivals the pure form ascorbic acid in terms of the results you're going to see. This product uses two really effective antioxidants alongside that 20% vitamin C derivative to protect the skin to give you that instant glow up and boost to radiance and luminosity, but to also deliver that hyperpigmentation fighting benefit that we really want from our vitamin C. The key to this one working so well though is plant derived exosomes. Exosomes are quite trendy in skincare right now, but I would see them as something which is almost like a vehicle for helping the active ingredients get to the skin to where they need to be in order to deliver those results. So see this as a serum that not only has those ingredients, but also the vehicle to target them where they're needed the most, which is why it's so effective."

"Of all the Medik8 vitamin C's, this is my favorite. It actually uses one of the highest potency vitamin C derivatives on the market, so you're really getting that gentle yet super effective dose of vitamin C. Vitamin C derivatives are much better for people with sensitivity-prone skin. You don't get any prickling or any sensitivity from this, but it gives you the nicest glow up. Use this for a week, and by the end of that seven days, you'll be glowing to the gods. Honestly, this has given me a better glow than any other vitamin C I've tried. It's got all the antioxidants in here, and because it's got exosomes in, that's how they get that vitamin C derivative to work so hard. They use those exosomes to really push the product into the skin and deliver it to where it needs to be in order to get that maximum results. This is something genuinely really special. I don't think I've skipped a single day since. If you hate the hot dog smell that usually comes with vitamin C, get this because it just has the nicest scent to it ever. Not hot dog watery at all. It's almost like a botanical scent to it."

"This bar none is the best glow enhancing vitamin C you will ever find. If you're using your vitamin C primarily to boost radiance and luminosity, stop right now. Look no further. This is like a glow up in a bottle. I have used this, I have loved it and I bought it time and time again. I'm on bottle maybe six now. My skin drinks it up. I tend to use a pure form vitamin C on a morning, then on an evening, I'll use a vitamin C derivative. This is a vitamin C derivative. Superb. If you have very sensitive skin, this won't irritate it. If you're looking for that glow up, this is the one for you. This is the first time I've reached for a product and realized yes, vitamin C derivatives can genuinely rival pure form vitamin C if it's done right. If a brand knows how to formulate and Medik8 really do, then you can get gentle but hyper effective vitamin C in derivative form. I love it. It isn't the cheapest out there, but we know that Medik8 sale is round the corner."

"This is the Medik8 C Tetra Advanced. This is a vitamin C derivative packed full of other great beneficial actives as well. I get the best glow from this. I've tried so many vitamin C's. This gives me the best glow. Because this is like an emulsion cream base, I find it works best at the end of my serums rather than the beginning. This has one of the nicest cream emulsion textures. It's going to work far better on top of say like another serum than underneath it. There's no prickling."

"If you're reaching for vitamin C to boost radiance and luminosity and glow in the skin, ditch the pure form vitamin C's. This specific derivative is the best on the market when it comes to brightening the skin. I've been using this for the past six months since it launched and it's been a game changer for my glow game. I absolutely love it. It doesn't have that hot dog water scent that pure form vitamin C's come with too. So if you don't like the smell of your vitamin C, give this a go. They've actually revolutionized the vitamin C derivative category, showing that some derivatives actually work better in certain circumstances than pure form vitamin C. This is one of them for your glow game. This cannot be beat. It's super gentle yet super effective, and that for me is groundbreaking. This is my now go-to vitamin C."

"This is just one of the best vitamin C's you will ever use. The reason this is special is it uses the highest potency vitamin C derivative that I think exists and pairs it alongside two different powerful antioxidants. You're getting that next level antioxidant protection for the skin, and that instant radiance boost and glow up from the formulation. That potent vitamin C derivative is going to fade hyperpigmentation and increase luminosity as you go. You're going to want to use it consistently in your routine for a good month before you see those results, but it's worth it. You can use this morning and evening, and you can use it alongside your other products such as retinoids and exfoliating acids. It's all fine. You can slap this on the skin and it genuinely delivers. The vitamin C derivative is in a 20% concentration which is skyhigh, and you've got those extra antioxidants. They also use exosome technology in here, which helps carry that vitamin C to where it needs to be. You don't need a ridiculously low pH for this to deliver. It's in a skin neutral pH."

"This is an amazing vitamin C derivative and I'd say if you're somebody that likes your vitamin C derivatives, this is going to be the very best you will ever use. For us derivative lovers, this is a powerhouse. You've got what I think is the most potent of the vitamin C derivatives, with so many other brightening ingredients in here too. And the best thing about this is despite the fact it has a sky-high percentage of that derivative, it doesn't sensitize and doesn't stress out the skin. It's in a really nice cream gel hybrid. A lot of the vitamin C derivatives have a very oily finish to them. This doesn't. This has a really nice gel cream feel and that I love. It disappears without a trace because of some of the natural extracts that it has in here. It has a really nice uplifting scent to which I really appreciate. This is definitely a powerhouse. I am completely in love with this and the second I'm done with my samples, a full size will be going on order because I never want to skip it."

"This is a 20% vitamin C derivative that is phenomenal for the way that it increases luminosity and it really helps to fade hyperpigmentation in a super gentle way. No prickling, no sensitivity, no irritation, but all the results that you would expect for a really well-formulated vitamin C. I absolutely love this product and I think this is going to be one of those rare products that genuinely suits all skin types, all levels of sensitivity. You've got your pure form vitamin C here in a formula which helps to keep it stable so it's not going to oxidize too quickly. You've got your ferulic acid, which is great in terms of providing antioxidant protection, but also further stabilizing that vitamin C."

"They've used a super high potency vitamin C derivative to give maximum results with minimum side effects and irritation. They've loaded this with other radiance boosting ingredients all working together to give you literally the quickest glow up you will ever achieve. Use this twice or three times and you will be glowing. Your hyperpigmentation will already be disappearing. If anyone tells you that vitamin C derivatives do not work, send them this product because this is living proof that vitamin C derivatives do work if you choose the right one, formulate it the right way, and deliver a quality product. This completely changed my perspective on vitamin C and Medicate will always have my heart for that."

"Medicate C Tetra Advanced uses acetyl zingarone, a super advanced vitamin C derivative that delivers ultimate glow. I was a skeptic when I started using this, but I was genuinely impressed. I don't get that much glow from a traditional ascorbic acid serum. This product gave me that real lit from within glow that I craved. It delivers far greater benefits than traditional ascorbic acid serum without the sensitivity, prickling, or irritation. Once opened, you have the longest shelf life possible because vitamin C derivatives don't oxidize. If you want that glow up and luminosity in the shortest possible time, this is a super effective option."

"This is the Medik8 C-Tetra Advanced. It uses a super high potency vitamin C derivative, the derivative that has the most data behind it in terms of how effective it is at boosting radiance and luminosity, in a base formula that further enhances that glow up. After just a week of use you'll have the nicest glow, that radiance, that luminosity, that lit from within glow we all crave, and it's phenomenal for sensitive skin. If you're somebody who says no to vitamin C because every one you've tried just doesn't work for you, try this, I promise you it will work and you will love it. It doesn't oxidize like other vitamin Cs and stays shelf stable for such a long time because it's a vitamin C derivative. It also uses exosomes to get that vitamin C into the skin to be more effective."