Price: $29.00
(as of Mar 21, 2025 12:16:10 UTC – Details)
From the brand
science backed haircare
Our professional stylist-approved biotech breakthroughs deliver your healthiest hair.
Engineered for all hair types.
Your Healthy Hair Routine
reverse hair damage
K18 molecular repair is cilincally proven to reverse damage from bleach, color, and chemical services in 4 minutes.
Who are we?
We’re a biotech-powered brand breaking the rules on haircare. Beloved by the PRO community and at-home users in 100+ countries, 20+ billion Tik Tok views, and 25+ prestigious awards, our growing line up of intentional, science backed haircare is all about unlocking next-level expression for all.
What makes our products unique?
Our K18PEPTIDE-powered innovations were born in the biotech lab to radically simplify your routine and deliver your cleanest, healthiest hair.
Product Dimensions : 3.15 x 1.57 x 1.57 inches; 1 ounces
Item model number : K18-31007
UPC : 858511001289 746559900490 858511001371
Manufacturer : K18
ASIN : B09HR5KSR8
Country of Origin : USA
Customers say
Customers find the conditioner effective and able to improve hair softness and shine. It makes their hair smoother and healthier, making it look and feel great. However, some customers feel it’s expensive and not practical for everyday use. They also dislike the bottle size. Opinions vary on its ability to repair, strengthen, and dry hair.
Maria –
Small & pricey but so worth it!
I wasn’t expecting it to be this small for the price haha! But it is an amazing product & by far the best leave in conditioner that has actually controlled frizz, and left my hair soft. I’ve bleached my hair several times which has obviously left my ends feeling like a straw, but this immediately left my hair looking healthy and hydrated. It does not leave your hair feeling thick and sticky and it smells great!
CurlyTop –
Very effective, will keep using from time to time
I have waist long thick curly hair, that tends to get dry and has been dyed from time to time – but it does not have damage from bleach or highlights or using lots of heat. So far I have used this 3 times, and the difference is very noticeable – my hair looks so much healthier, shinier and more bouncy. I am planning to use this 1-2 more times in a row, and then switch to a maintenance mode of using it maybe once a month, as needed.Tip on how to use it -you need to put it in your hands, then rub the hands together so it emulsifies and almost looks like you smeared white toothpaste on hands. Then apply it to hair, starting with the ends and moving up. I didn’t know that the first time – it makes a big difference, as opposed to simply applying it out of the bottle. I am using 3-4 pumps each time, since my hair is quite long.
Kieley Sue –
This stuff is a miracle!
This stuff is an absolute miracle in a bottle. It has fixed my hair after an unfortunate visit to a salon which left my hair extremely bleach damaged hair. Seriously my hair felt synthetic after and looked fried. I noticed a difference after only using the product one time, which is only 4 squirts from the bottle. My hair was so soft, shiny, not a tangled hot mess and just looked healthier.I bit the bullet after seeing this all over social media. Is it spendy? Yes. But I would gladly pay again an again for this vodoo hair repair. Now that my hair is “fixed” I only use K8 once a month and I will never be without.
nicole –
Savior
I cannot rave enough about the K18 Hair Mask—it has truly saved my hair! I used to pull my hair every day, causing so much damage and breakage. My hair was dry, brittle, and lacked any real shine or strength. After using this mask for a few weeks, the difference is incredible.The formula is super easy to apply, and a little goes a long way. I’ve noticed my hair feeling softer, looking shinier, and overall much healthier. The breakage has dramatically reduced, and the texture has improved—my hair feels stronger and more manageable. It’s as if the mask has repaired the damage I caused over time.I now look forward to hair care days because I can actually feel and see the difference. If your hair has been through a lot, this mask is a game-changer! It’s well worth the investment, and my hair has never looked or felt better. Highly recommend!
GraceIsTheKey –
It works!!!!
Went from box dark brown neutral dye, to blonde in one sitting. Damage was present. I walked out with bangs! HAHA. I told myself no more bleach after this. I bought K18 leave in the same day and have used it 1-2x week post shower, and I will be going back for bleach. At first I was barely able to brush through my hair now it feels back to 80% health. I am amazed by this product and will be buying the full size. Expensive, but worth it!
Amazon Customer –
Fall in love with K18 for lots of $ LOL
I fell in love with the K18 Leave-In Molecular Hair Mask about a year ago after my hairdresser introduced me to it. While it’s on the pricier side, its effectiveness and quality make it worth every penny. When I’m unable to splurge, I turn to my regular leave-in spray, Perfect 10 Lite.As someone with thin, color-treated hair that tangles easily and suffers from damage, this product has been a game changer. It shortens my shower time, extends the life of my conditioner, makes brushing my hair effortless, and leaves my hair looking healthy once styled.I recently purchased the larger size, fully aware of the cost. However, when I opened my package, I briefly thought I either ordered the smaller size by mistake or received the wrong item. I realized it was indeed the larger size I ordered and I debated returning it.The true test came when I woke up with a legit rat’s nest. I was so thankful I had this product on hand, as it made detangling much easier than previous times when I had nothing to help with the mess.One note: I read a review suggesting that you should rub the product between your palms to activate it before applying it to your hair. That makes sense, and I’ll definitely give it a try. However, I find it quite unethical that the company leaves this step out of the instructions on the box and bottle. It feels like they might not want you to use it correctly so that you’ll need to buy more sooner—quite disappointing!
ella –
amazing
very good product, but the packaging is REALLY small for such an expensive product but next time i buy i’ll get the bigger size. my hair usually feels synthetic because of all my damage but this made it finally feel real. i use it once a week (i only wash my hair once a week) and the results have been phenomenal.even though the packaging is really small, it lasts because a little bit goes a long way with this product. i absolutely loved this 10/10 will be buying again
Anonymous –
Not sure if it’s good for coarse curly hair in transition.
I was really skeptical at first because it felt so odd to shampoo and not condition after.. but I followed its directions: I shampooed, towel dried my hair, and put this product in and left in for the 4 minutes.My hair did feel softer, less rough, yes, but I have a lot of coarse curly hair (transitioning from heat damage) I had to use like 7 pumps and this product is expensive. It made like 80% of my hair feel soft and the rest of it i had to use another leave in conditioner to take out the tangles my hair has. It’s an ok product but it’s my first time using it. Will continue using it!
KP –
My hair was very damaged and whole this product is fairly pricey I felt that it really helped repair my damaged hair
Sam –
BEST PRODUCT EVER. I can’t remember how I found K18 but honestly I will never go back to anything else. I have very long hair & was looking for something to help with the texture/smoothness after I got highlights. I had another mask before this that was good but this was like a little miracle worker.I don’t use it every wash because it is a bit pricey and I have a LOT of hair to cover lol. But right after getting highlights I’ll use it once a week for about a month to repair my hair. Then I’ll only use it if I’m going out for a nicer occasion or I feel my hair needs a bit of help.I focus it mainly on the ends.I’ve gotten so many compliments on how beautiful my hair is/how soft it is since using this!I love that it’s so easy, no rinsing it out or anything.I do wish it came in even a larger size (I know they have this travel size and the slightly bigger one) but I would love an even bigger bottle!Also side note, I didn’t have my hair cut in 3 years and used this during the later months of that time period, and when I finally went to have it cut, my hair dresser was shocked by how healthy my hair was for it being 3 years. She went around telling everyone she couldn’t believe it. 😆Anyways, long story short, buy this product! You won’t regret it!!My Exact Routine for Soft Shiny Hair:1. Wash hair well with shampoo (I use the Aussie brand) (I often wash twice with shampoo because I wash my hair fewer times a week, scrub really well). Don’t use conditioner.2. Gently towel dry hair after. Brush hair before or after K18 (it’s easier after if you’re lazy sometimes like me, lol) Use K18 as directed.3. After k18 has had time to sit on your hair, you can put on a leave in conditioner. I use the Marc Anthony Coconut & Shea.4. Blow dry hair. (My hair is naturally quite straight when blow dried so feel free to straighten or curl yours after this step if needed).5. Take a small amount of Renewing+ Argon Oil of Morocco and run it through the ends of your hair mainly. Then use any small excess amount to run through your hair over any strays. Brush through your hair after to evenly disperse it.5. Finish with a spray of AG Hair Care Argon Shine & Flat Oil Spray. This stuff makes your hair shine! Even if you’re going for a curly look, a little spritz of this just adds a nice sheen to your hair, making it look healthier and more alive. (A friend of mine actually borrowed this once because her hair was a bit frizzy and later asked me what it was because she loved it so much).Comb it through your hair and you’re done!Hope this helps someone! ☺️
Bree Lopez –
No sé que tanto les sirva mi review, pero aquí va.Tipo de cabello: delgado, grasoso, longitud media- larga, virgen pero un poco reseco de las puntas y sin brillo.Como puedes ver arriba, mi cabello no estaba en una condición crítica. Sólo estaba buscando que se viera más brilloso y saludable así como tener una rutina de cabello.Después de ver muchos reviews en YouTube, lo compré con descuento.Yo no sabía que necesitaba esto, hasta que lo compré. Me dejó el cabello muy suave, manejable, sin frizz y brilloso. No es lo único que uso ya que, como dije, me hice una rutina de cabello y me ha dado los resultados que estaba buscando, pero definitivamente esta fue la piedra angular de todo esto.No sé te olvide usar un shampoo clarificante antes, exprimirte muy bien el cabello, frotar el producto hasta que se vuelva blanco y luego ponerte el tratamiento. Yo probé tanto ponérmelo mientras me baño, como después y la verdad me gusta más mientras y después de esperarme unos 5 minutos, ponerme acondicionador.Recomendado 100%
Ana Rodrigues –
Recupera bem o cabelo. Produto incrível. A entrega atrasou por culpa dos correios já que o vendedor postou o produto rápido. Produto veio bem embalado, lacrado e com manual de instruções. O tamanho é bom, vai render bastante. Essa é a segunda vez que compro o k18 e a primeira desse vendedor e gostei mais desse porque veio lacrado e com manual de instruções.
Audrey Lonni –
Produto muito eficiente, que vale o alto custo. Atua revertendo o dano no fio capilar.