Leave-In Molecular Repair Hair Mask.

"Another bond repair treatment I use regularly is K18. I actually discovered this before a prey and it really started my journey back to soft hair. Now, this is a bit trickier to use. It likes towel dried hair, which then has to be rinsed off. So, for me, it's only once or twice a month, but I keep buying it and I was super excited when they launched this big guy so I don't have to repurchase the smaller ones as frequently."

"K18 if you haven't used it in the shower it's just an amazing Bond repair product"

"I love this and I specifically use this right after I get my hair colored. I will use this for three or four showers and it's a bond repair program. I prefer this to [Olaplex]. I stopped using [Olaplex] and I use this instead. I think it's fabulous. What I tend to do is I shampoo my hair, you do not condition it first, you shampoo and then you put this mask in and you leave it in for four minutes. I put my hair up and then I do shaving and all the other stuff on my everything shower days and then you rinse it out."

"Another fantastic Bond repair product is the K18 Leave-In Molecular Repair Hair Mask. I've been using this even longer than the appre and I actually find that using them together it's the perfect pairing they repair Bonds in different ways. One is pre-shower and then the K18 I use during the shower and I love them both."

"The K18 Leave-In Molecular Repair Hair Mask is another little miracle worker that repairs hair bonds. It's another one I've never without, automatic repurchase. I use it in the shower, and when it comes to pairing these items, I use the other product before I get in the shower and then I use the K18 in the shower. It may be high maintenance but my hair thanks me and I don't care."

"I am one hundred percent dedicated to the bond repair mask. It's always in my shower, I use it generally three times a month, and I've been doing so for years and years and years and years."

"I had heard such wonderful things about K18. So, I decided to try their molecular repair hair mask. And it really just made a huge difference for me at that time. In particular, it contains a peptide that helps to reapproximate damaged bonds from heat styling, color treatments. It works not only across the hair strand, but down the length as well. So, it helps improve smoothness, shine, manageability. The way you use this kind of trips people up. You use it after you shampoo the hair, but you do not want to condition. Then, you get out of the shower, you towel dry the hair, and you just use a few pumps of this product. A little bit goes a long way. You distribute it all over the strands and let it sit on there for 4 minutes. After the 4 minutes, you can put on a leave-in conditioner or whatever styling product you want. [...] The reason you don't want to put conditioner on before though is that it'll keep the active ingredient in the hair mask from really being able to access the strand optimally and for you to get the best results. [...] I used it a lot in order to kind of correct that damage and make my hair a little bit more manageable."

"The K18 Leave-In Molecular Repair Hair Mask is one of my favorite bond repair products. It works by having an actual mechanism within the ingredients that helps to temporarily reapproximate damaged bonds in the hair. [...] I put this one through the test, and [...] this product works. It does what it says it's going to do. Not only does it work, it works well."

"I love the K18 Leave-In Molecular Repair Hair Mask. It works to reapproximate the disulfide bonds to help cut down on frizz, brittleness, breakage. If you have damaged ends from doing a lot of heat styling, it's great. I mean, it really works."

"This product really works. What it does is it helps to reapproximate bonds in the hair. It works along the length of the hair and along the width of the hair. And what that does is help to mend damaged hair from heat styling, dyes, chemical processing, and it really works. The [...] way to use it is you shampoo your hair like you normally would. Then you do not want to put on conditioner. The reason you don't want to put on conditioner is because if you put conditioner on, then the mask ingredient will not be able to access your strand. So [...] when you get out of the shower, you towel dry the hair so it's just a little damp. And then all you need is like three pumps. You don't want to use too much because it'll actually kind of weigh down your hair. Just three pumps to the entire strands. And then you leave it on for approximately 4 minutes. And then you can do whatever you want to your hair. You can put a leave-on conditioner on if you feel like you need more conditioner. But honestly, this conditions [...] by reapproximating those bonds like that."

"You could also try using a bond repair product. I have personally had good success with that popular K18 hair mask. These just help to re-approximate temporarily the bonds in the hair, especially if you have color treated hair with a lot of damage that ends up getting frizzy in humidity, [...] or excessive heat damage on the hair. [...] The K18 hair mask is not heat activated, unlike the other options."

"I will add in probably you know in that routine like once a week a bond repair treatment like K18 or something like that."

"The one product that I keep getting from Sephora over and over again [...] is the K18 Leave-In Molecular Repair Hair Mask. I love the fact that it comes in different sizes now, so if you're not willing to take this splurge -- because it's not cheap -- you can try a smaller size or restock on the travel size. But this is literally the peptide bond repair treatment that has turned my hair around. I really love the science. It's got this unique peptide that penetrates your hair, and you can use it different ways. Before, I would use it as a leave-in mask after shampooing -- I don't condition -- then come out of the shower, apply this, wait 4 minutes, and follow it with my styling products. For some people who find that not moisturizing enough, you can use it as an in-shower treatment: leave it on for 4 minutes, rinse it off, and follow with your traditional conditioner and the rest of your routine. [...] I also find that when you use it more regularly in the beginning, you can space out your treatments. Now I only use it maybe a few times a month. But yes, this is the repair product that has completely changed my hair. Highly recommend it if your hair is damaged, over-processed, or over-colored -- this is the one to try."

"I absolutely love and splurge on all the time. It's a great gentle detoxifying shampoo with the K18 trademark peptide that really helps to remove buildup, that really helps to clarify your scalp and your hair and prep your hair for the K18 treatment, but at the same time doesn't make your hair feel really stripped or dry. It removes up to 99% of product buildup, 95% of seabum buildup and the other kind of hard minerals that you may get from the water or pollution. So it is really one of the most gentle detoxifying shampoos, but at the same time works well at removing everything."

"Apply a pump or more depending on the length of your hair to your entire hair and wait for 4 minutes before applying other styling products. This not only helps repair but conditions your hair at the same time. Compared to other hair repair treatments, I personally have had the most noticeable improvement in my hair when I use this consistently. You can use it like once a week or a couple of times a week. It's certainly pricey, but it's a great one to buy during savings events. It's a really rich, dense hair mask that is not overloaded with protein, which I appreciate because some individuals are protein sensitive and a lot of protein can build up and weigh down your hair. This is more rich in plant-derived extracts and oils that are nourishing and conditioning, and you definitely do not feel your hair is weighed down afterwards."

"K18 is probably one of my favorite hair care lines from Sephora and really has wonderful science behind their formulation. I use it regularly and it's really a line designed to help repair chemically processed damage hair from coloring, heat styling, frizzy hair, and breakage. This set contains their popular K18 Leave-In Molecular Repair Hair Mask along with the miniature hair oil, and basically both products contain their signature K18 peptide that's been shown to really get into the hair to help temporarily strengthen and repair hair, and over time actually has been shown to really make that more permanent change to helping reduce hair breakage. I also love the hair oil because a few drops go a long way and really helps to act as a heat protectant, helps to smooth down hair, reduce frizz, and also has avocado oil that helps to soften and nourish hair at the same time."

"After washing, I apply that treatment as a treatment and leave-in conditioner in one and I don't feel that I need any additional conditioning afterwards. [...] This K18 treatment is really one of the best things I've done for my hair when it comes to bond repair treatment. It really has turned my hair around from all the coloring and chemical processing and heat styling. [...] You can use it once a week, but in the beginning you can definitely use it more consecutively, like up to four times, to really get that good result. [...] If your hair still needs more conditioning after using it, you can rinse it off after four minutes when that bond repair has fully penetrated into your hair [...] and then condition if you need to, but I personally don't need to do that."

"K18 Leave-In Molecular Repair Hair Mask is one of the key products that have transformed my hair. [...] I use this quite a bit in 2023 and throughout 2024 and I do feel like ever since I started using it I have noticed a significant difference in the overall quality and health of my hair. [...] The reason why I love this is because it's worked really well and really it's the convenience of use that's probably really why I've used it so much. [...] This does have really cool science behind it and the people that developed this product come through kind of a library of all the peptides that we know kind of affiliated with hair."

"K18 is one of my favorite hair repair brands and this leave-in mask really hands down has transformed my hair it is one of my favorite bond repair products. This would be great for anyone that has like dry damaged hair, anyone that like me colors their hair frequently or styles their hair frequently and is looking to do some really effective repair. This comes in a 15 mil hair mask that really has their proprietary K18 peptides. So this brand actually has done research looking at thousands of peptides and sequences and really found the one that is effective at getting into your hair cuticles and helping to make some amazing changes in repairing the bond and strengthen your hair, which is why I think like me and many other people really feel that K18 works really well for repairing damage."

"K18 Leave-In Molecular Repair Hair Mask I've been using for the past two years now and it has made the biggest difference for my hair and the structural component of my hair. This is a leave-in conditioner so what you do is you wash your hair shampoo your hair and then you apply this mask from root to the end and then after 4 minutes you can apply or style your hair as usual. You can use this on a daily basis like four times a week until your hair gets to a good point and then use it as needed. At this point I probably use it like once a week. When I was really aggressively trying to repair my hair I was probably using it maybe two to three times a week but I feel like it has definitely made the biggest difference for me. It's nice because it not only works like a leave-in conditioner so helps to instantly soften reduce frizz help to detangle make your hair manageable but over time it does do wonders for your hair if you have like me like brittle dry damaged hair."

"This is a must in my hair care routine. It really helps to strengthen and repair the bonds of your hair. Because I'm blonde, I feel like this is a must for me personally. [...] If my hair appointment is coming up, I will use this about two times before my hair appointment just to strengthen my hair. And then post hair appointment, I will use this six hair washes post hair treatment to really strengthen and repair my hair from getting my hair highlighted. Ever since doing this technique, and I've been doing this now for over a year, I've noticed a big difference with my hair. My hair actually grows, my hair doesn't break, and it really keeps my hair strong and healthy looking. My hair isn't frizzy either. It really has improved my hair. Just be patient with this and use it and be consistent. Within a couple of months, you really should see a difference with your hair. [...] You don't need to use this every day. You may want to use this a couple of times per month. It really just depends on you. I put about a pump, a pump and a half into my palm. This was the collaboration with Future Society, which is a limited edition scent. It smells so good, it smells way better than the original K18 Leave-In Molecular Repair Hair Mask. I really hope that they keep it long term because it's really nice."

"I've been using this now for pretty much two years, and this is the one product that has honestly transformed my hair. [...] It has brought the health back, it makes the ends of my hair a lot stronger, and it does a really good job to repair damaged hair as well. I usually use this as maintenance throughout the month. I don't use it every time I wash my hair, but if I have a hair appointment coming up, I will be consistent with it for the first two to three washes before my appointment. And then after I've had my hair highlighted, I will use it for the next six washes post-appointment to really strengthen the ends and just bring the health back to my hair. [...] Ever since I've been doing that, I've noticed a big difference. My hair is just shinier, softer, it looks a lot healthier, and it really is coming from this product. I usually do two pumps, and you want to warm it up in the palms of your hands until your hands are white, then apply it to your hair. I focus mainly on mids to ends and my bangs because those are generally the areas that can be a little drier and a little more frizzy."

"I apply it to mids to ends and I apply it in my bangs and I leave it in my hair for like 5 to 8 minutes, maybe 10. Then I rinse it out and my hair just feels so silky. It really makes a big difference. [...] The K18 Leave-In Molecular Repair Hair Mask is a non-negotiable. This will truly transform your hair. I have been very consistent with this over the last year, year and a half, and I have truly seen a big difference with my hair. I have been through the ringer with my hair. I've dealt with a lot of breakage and dryness several years ago, and my hair is starting to look and feel so much better. And I really do feel like the K18 brand has really made my hair become the way it looks now. Especially this product right here. [...] After you've done your hair care routine in the shower and you hop out of the shower, towel dry your hair and then put maybe one or two pumps of this in your hair. [...] I will do this maybe once a week, once every other week. But if I just got my hair done and I just got highlights, I will use the K18 mask every hair wash for the next six hair washes to strengthen the ends to bring that shine and health into my hair. And this is where I have noticed a big difference with my hair."

"This is the K18 Leave-In Molecular Repair Hair Mask. This really does work to repair damaged hair and to repair the bonds of your hair. I like to use this sometimes several hair washes in a row and then I might take a break for a few weeks and then start back up again. This is a great product to use even after your hair appointment just to strengthen your ends, especially if you've noticed that you have a little bit of damage or maybe your hair's feeling a little dry. This is incredible and it really does make your hair super soft and shiny, and eventually with consistency, like this can totally repair the hair and make it look healthy. I will be purchasing another one because I feel like this does the job really well."

"Since being really consistent with K18, honestly, this has really improved my hair. And then after the six hair washes, I'll take a break for a while. And then just before I go back to the hair salon again, I will use this one or two times just to strengthen my hair up again. [...] This really is gamechanging whether you have blonde hair or not. This can really improve the bonds and I love it. Every time there's a sale, I always stock up."

"This is a must-have. This is a product that actually works. That is worth the money. This is a product that will help to repair damaged hair. It helps to strengthen the bonds of your hair and it also helps to add shine and keeping your hair looking as healthy as possible. After I've just had my hair colored I like to use the K18 Leave-In Molecular Repair Hair Mask consistently for the next six hair washes to really strengthen my hair to repair the hair because sometimes when I go blonde my hair can be a little dry and sometimes I can experience breakage as well because I have fine hair. So this is something that I will use for the next six hair washes post appointment. After that I might only use this maybe two or three times per month."

"I will use this once or twice before I go and get my hair done. And by doing that, I have noticed a really big difference with my hair. I have pretty fine hair, so I need to be careful when coloring it, when heat styling my hair, and this has made a huge difference. So, this is a non-negotiable. This always needs to be in my collection."

"For bond repair, I love the K18 Leave-In Molecular Repair Hair Mask. This is not your typical deep conditioner. It's a biomimetic hair treatment that repairs broken hair chains at a molecular level and restores the strength and elasticity. It works in just 4 minutes to help reverse the damage from bleaching, coloring, heat, or any chemical treatments. Unlike traditional bonding treatments, K18 permanently reconnects keratin chains for lasting damage repair. The key ingredient is the K18 peptide, which is a patented peptide that mimics natural hair structure to rebuild keratin proteins."

"The K18 Leave-In Molecular Repair Hair Mask is my first recommendation in the hair care category. [...] It can be pricey and comes in a tiny package, but it lasts a very long time. [...] This is not your typical deep conditioner. It's a biomimetic hair treatment that repairs broken keratin chains at a molecular level, therefore restoring strength and elasticity. It works in just 4 minutes to reverse that damage for any bleaching, coloring, heat, or any chemical treatments you may have done. Unlike traditional bonding treatments, it permanently reconnects those keratin chains for longer lasting damage repair. The key ingredient is the keratin peptide, which is a patented peptide that mimics natural hair structure to rebuild those keratin proteins."

"The K18 molecular hair mask, [...] you just use a little bit. [...] In the shower, wash your hair, don't apply conditioner, and then when you get out of the shower, I'll just apply a dime-size amount, rub my hands together, and then just apply it to the very ends of my hair, and it does a nice job. This is more for color-treated hair, permed hair, damaged hair. If you don't color treat your hair or perm it or do anything like that, there's I think this might for some people end up making your hair worse off. I've heard certain proteins and peptides if you use them on hair that's not damaged it can make it worse."

"You use things like Olaplex or K18 mask, things like that to help heal those damaged bonds"

"Their leave-in conditioner mask is nice. One thing I want to mention, I haven't repurchased this more than a couple times because I use such a small amount of this. [...] The bottle is 1.7 oz, so I literally use almost a pea size, which I can't get away with doing almost pea size with almost anything, but with this one it works well. It's the K18 hair mask, it's really nice. It's expensive, but literally I've been working on this bottle for probably a year now. So it would be repurchased if I used a ton of it at a time, which I don't. It's very nice and I like to use a good clarifying shampoo before this because I feel like it soaks in more and works better. So it's just a leave-in product, so you rinse with shampoo, don't apply conditioner, and then apply this."

"This stuff is expensive. It's 75 bucks, but I will say it lasted the last bottle last me about two years, and I just use it once a week. I'll shampoo my hair, don't put conditioner in it. When I get out of the bathtub, I'll put like a half a pump on my hand and just smooth it into my hair. It's just a leave-in treatment for bleached, colored, permed, or treated hair. Don't want to use it too much. If you don't have damaged hair, you probably don't need it and don't want to use it and don't want to spend the $75 on it. I've read where people that have perfectly fine non-color treated, non-perm, non-treated hair that will go and overload on some of these protein and peptide things and their hair will end up being damaged afterwards. So if you don't need it, don't use it because sometimes it can actually be more harmful than any."

"The K18 hair mask is always very expensive in Canada, it's over a hundred dollars for this mask. I got this for my hair stylist for I think 50 bucks which I thought was a lot. I mean it does last a long time because you use such a small amount, but 101 dollars for a hair mask, I mean it's a good thing it's a good product, but there's no way I could ever justify a hundred one dollars for a hair mask. I mean the ingredients in here aren't like anything. I mean sure they had to do research and development things like that, but something just in there in my gut thing makes me think there's something else going on there."

"I use the K18 Leave-In Molecular Repair Hair Mask that one only on the lengths after washing. Other than that, before bed and before I brush my hair."

"The K18 Leave-In Molecular Repair Hair Mask is one I picked up about two years ago and I feel it helped my hair get even better. I've since sized up to the full size and use it during the week, since you don't condition beforehand, you just apply it and let it sink in. After 10 minutes I go in with some hair oil to detangle and nourish, which saves me time in the wash process over the week. I like it and have already repurchased."

"The k18 Leave-In Molecular Repair Hair Mask claims to repair hair damage caused by bleaching, heat styling, and chemical services by reconnecting broken polypeptide chains at a molecular level, offering both immediate and long term results. The texture is lightweight and creamy, more like a leave-in conditioner than a thick hair mask, with a subtle, slightly medicinal scent that fades quickly. If I didn't follow up with additional products after the four minute wait, the result was underwhelming, my hair felt dry, frizzy and slightly coarse to the touch, so using it on its own absolutely did not work for me. After three months of using it, my hair feels healthier and there is less breakage around my ends, and comparing pictures from three months ago to now, my hair definitely hasn't gotten worse. After several weeks of using it, my hair does feel stronger and less prone to breakage, though it's not a magic bullet that will completely erase years of damage. Despite the high price, I will repurchase it. I think it's a worthwhile investment for anyone with damaged, bleached, or chemically treated hair, particularly if you're dealing with thinning or breakage, and for those with very fine hair it's lightweight enough that it won't weigh your hair down. However, if your hair is already in great condition, you might not see dramatic results that justify the cost. The first few times I applied it the results were underwhelming, in fact I nearly stopped until I learned I could follow up with leave in products once I had let it sit for four minutes. If it is short term results you are after, this is not the product to reach for, but if you are willing to believe it will repair your hair long term, it could be a game changer. Just be prepared for a bit of a learning curve in terms of finding the best routine to suit your hair's unique needs."

"The k18 Leave-In Molecular Repair Hair Mask is a new discovery from 2024. I [...] use it in addition to [...] the Olaplex No 3 Hair Perfector, [...] on alternating washes. Olaplex has more of an immediate effect while K18 seems to have really improved the health of my lengths."

"K18 kind of entered the scene a few years ago and I named it as a monthly favorite in 2022 in the spring, I was really enjoying it then. It's a similar concept to [Olaplex]. I think it really helps to strengthen my hair and helps to keep it in really good shape. I think it helps to resist some split ends and damage on my hair as well in between trims. It's really expensive, it's retailing $75. That is not what it retailed back in 2022, it was still pretty pricey, I think it was pushing maybe $60, which is still I think too much. They raised the price recently. I don't really understand why this is so freaking expensive. It is nice but it's tricky to use, unlike [Olaplex] where I can just put it in my hair."

"I've been using this for a few years and just over the last year, year and a half, I've been using this almost exclusively. [...] After washing my hair and conditioning my hair, I will use this as a leave-on treatment. I use one pump for all of this hair, [...] work it on my ends and then through the mids. [...] You just leave it in. It is a reparative strengthening bonding hair product and it does work very very nicely. One way to use this is to actually replace your conditioner product with this."

"I used the K18 Leave-In Molecular Repair Hair Mask right after washing my hair and before blow drying it. [...] I slept on this hair, washed it last night dried it and slept on it, and there's still some nice volume at the roots. I like how this lasts."

"This product actually can enter the hair shaft and repair from the inside out. Even though I bleach my hair and I heat style my hair for many years, I did nothing to repair the bonds within my hair and my hair was fine. But then I tried K18 and I was like, 'Oh, my hair could have been doing so much better this entire time because when it repaired those keratin chains, the first thing I noticed is that my hair texture came back.' My natural hair texture is sort of like wavy and it's a pretty nice wave. But after years of bleaching and styling, my hair texture was sort of this flat frizzy. It just was very unappealing. So when I use my K18, I see my hair texture return. And then it's so much shinier and bouncier after I style it. Because I'm refortifying those keratin chains periodically, my hair is able to grow longer and healthier and not keep breaking off in the middle. They recommend you use it for four consecutive washes to sort of kick off your journey and then use it as maintenance thereafter. So, at this point in my hair care routine, I use K18 about once a month."

"I think a lot of people are familiar with the K18 Leave-In Molecular Repair Hair Mask. And this uses a patented K18 peptide, also known as SH oligopeptide 78, to repair the hair. That peptide actually mimics the natural keratin structure of hair and can enter the hair cortex and repair those broken keratin connections. And the beauty of this is it's not just a temporary fix. This can offer a permanent solution in terms of repairing the hair strand."

"One of my all-time favorites and nothing has really surpassed this yet is by K18, their leave-in molecular repair mask is so so good and when I use that consistently I truly see a difference in my hair. My hair is long, it is bleached, I heat style it all the time, so if it is not looking good or if it is looking good it's pretty obvious. Because of the nature of my job I am constantly trying new hair care products and when I use something that I don't like I always go back to my K18 bond repair to reset things."

"K18 is really kind of my go-to. It is a peptide treatment that is meant to penetrate into the hair shaft to help repair damaged bonds. Within your hair shafts you have thousands, millions of keratin protein and those keratin proteins can get damaged and they can become unstructured in a way where it makes the hair look dry and frizzy and prone to breakage. The whole point of the K18 peptide is really to get in there and repair those keratin chains as well as repair disulfide bonds, which is another type of bond in the hair that gives it integrity. If someone has dry hair, damaged hair from heat styling or color treating or sun exposure, then using something like K18 in your regimen I think could be amazing."

"The K18 Bond repair treatment is kind of my holy grail for many many years. I'm a huge fan of that product."

"K18 is a bond repair product. When you are harsh on your hair, whether it's through sun exposure, pollution, heat styling, bleaching, or coloring, the bonds within your hair that give them strength and flexibility break. Having a bond builder in my routine to help restore those bonds and re-strengthen my hair has been a game-changer. I do K18 about once a month, except after I get my hair bleached, when I will do four rounds of it, using it with every hair wash for four rounds before going back to once-a-month use. When I first bought this, I was like, 'Wow, that feels kind of pricey,' but then it took me so long to go through a bottle because I use about one and a half pumps for my entire head."

"The K18 Hair Repair Mask uses a keratin protein to help restore the keratin protein in your own hair. I've had so many of you message me about this and been totally in love with it. These are types of investments that tend to be more expensive than shampoos or conditioners, but they have been proven to improve the hair structure, so it may be worthwhile if your hair is damaged or you feel like you could optimize your hair a little more."

"This product uses their proprietary K18 peptide to help repair the hair. Hair repair systems and hair repair technology don't work for everyone but for people who they work for they love it and I've had plenty of people tell me that they've used the K18 product and noticed a drastic improvement in how their hair both looks and feels. If you're interested in optimizing your hair I have an entire YouTube video dedicated to teaching you how to achieve your fullest healthiest hair. If you're sitting here going you know I've tried a lot of things for my hair I haven't found much success in how to repair it or how to make it feel or look healthier I think K18 is worth a shot and why not try it while it's on sale."