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full-size leave-in molecular repair hair mask
Description
A leave-in treatment mask that works on the molecular level to reverse hair damage in just 4 minutes. The K18PEPTIDE™ is clinically proven to repair damage from bleach + color, chemical services and heat* – with immediate and lasting results to restore strength, softness, smoothness and bounce to hair.
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*Disclaimers
2. Apply 1-3 pumps based on your length and density, starting at the ends and working up towards the roots.
3. Let sit for 4 minutes. Do not rinse out.
4. Comb, add styling product + style as usual. Use for 4-6 washes, then as needed.
*k18hair.com/disclaimers
The Science Behind K18 Molecular Repair
See how our K18PEPTIDE™-powered mask reverses damage in 4 minutes for lasting + progressive hair health.
molecular repair for aging hair
Hair evolves with age. This is how to support your strands throughout the years.- KanietSE K.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50mLI recommend this productAge 25 - 34Hair Concern Chemical damageHair Type Fine/ThinMy Results Less BreakageRated 4 out of 5 stars2 days agoAfter perm
After an unsuccessful perm, I took this mask. As it is written in the instructions, I applied only it 6 times in a row. I'm glad that the smell of burning from my hair is almost gone. Visually, the changes are not as clear as I would like, but I will continue to use. I’m sure it would be better if I give more time
KK18Hair2 days agoThank you so much for taking the time to share your experience with the Leave-In Molecular Repair Hair Mask after your perm situation, KanietSE! We're really glad to hear that you're already noticing the burning smell is almost gone — that's definitely a positive sign that the mask is working to repair the damage at a molecular level.
We completely understand that visual changes can take time to become more apparent, especially after chemical damage from an unsuccessful perm. You're absolutely right that giving it more time will likely bring better results. The molecular repair process works progressively with each use, so continuing with the treatment as you're doing is exactly the right approach.
We really appreciate your patience and persistence with the treatment, and we'd love to hear how your hair continues to improve as you keep using the mask. Your hair has been through a lot, so the fact that you're already seeing some positive changes is really encouraging!
- Lisa T.Verified ReviewerReviewingJumbo Leave-In Molecular Repair Hair Mask 100mLI recommend this productAge 35 - 44Hair Concern Chemical damage, Color-care, Frizz, Fragile/brittle hair, DrynessHair Type Fine/Thin, Medium Density, Straight/WavyMy Results Visible Difference, Stronger Hair, Soft Touchable Hair, Shinier Hair, Defined Curl/Wave PatternRated 5 out of 5 stars4 days agoAfter one use
I recently bleached my hair and have toned it a few times. The first picture is before, and then after one use of K18. I used a clarifying shampoo and then applied the K18 on damp hair. I was nervous about having to brush it after (clarifying without conditioner) but it combed through so easily.
I feel like the visual appearance, structural strength, and overall uniformity of my hair have improved by at least 20%. The more porous areas looked dull before, and I’ve already noticed more brightness and better blending. Overall, my hair looks and feels healthier and noticeably more reflective, without feeling coated.
I honestly think this product is amazing and well worth it. You can buy product after product that improves your hair maybe 5% or less, and sometimes the results are only temporary. Or you can get this and have real, noticeable results.
Wish I could have told myself this sooner.
KK18Hair2 days agoThank you so much for your incredible review, Lisa! We're absolutely thrilled to hear that our Jumbo Leave-In Molecular Repair Hair Mask delivered such amazing results after just one use - there's no better compliment than knowing our molecular repair technology helped restore the structural strength and brightness to your bleached hair while making it so much easier to comb through without that coated feeling! It's so exciting to see that you noticed a 20% improvement in visual appearance and uniformity, especially in those more porous areas that were looking dull before. We love that you're experiencing real, noticeable results that go beyond the temporary fixes - that's exactly what our peptide technology is designed to do by working at the molecular level to repair damage from the inside out! ❤️
- Noemi C.Verified BuyerReviewingK18 x Future Society Limited Edition Scent MaskI recommend this productAge 25 - 34Hair Concern Chemical damage, Heat damage, Color-care, Fragile/brittle hair, Split-EndsHair Type Fine/Thin, Curly/CoilyMy Results Less BreakageRated 5 out of 5 stars4 days agoSmells good
I love the smell of this I used as instructed and have been using for one month
I have noticed some improvement in my hair will update after more months of use. I recommend you use another product to soften your hair because this product will make your hair feel more dry.
KK18Hair2 days agoThank you so much for your incredible review, Noemi! We're absolutely thrilled to hear that you're loving the scent of our Limited Edition Scent Mask and that you're already noticing some improvement in your hair after one month of consistent use - that's exactly what we love to hear! ❤️
We really appreciate your honest feedback about the texture experience. Since our molecular repair mask works differently than traditional conditioners by focusing on rebuilding hair's internal structure, some people do find it helpful to follow their usual conditioning routine for that extra softness while the peptide technology does its repair work. Thanks for sharing that tip with other customers, and we'd love to hear your update after continued use!
- Rebecca M.Verified BuyerReviewingLeave-In Molecular Repair Hair Mask Deluxe SampleI recommend this productRated 5 out of 5 stars1 week agoMakes me hair feel like silk!
I love this stuff! I’ve got wavy, bleached hair and this is better than olaplex! Makes my hair go from hay to silk!
KK18Hair6 days agoThank you so much for your incredible review, Rebecca! We're absolutely thrilled to hear that our Leave-In Molecular Repair Hair Mask Deluxe Sample is transforming your wavy, bleached hair from hay to silk - there's no better compliment than knowing our molecular repair technology is outperforming other treatments and giving you that luxurious silky feel you deserve! ❤️
- Olena F.Verified BuyerReviewingLeave-In Molecular Repair Hair Mask Deluxe SampleRated 3 out of 5 stars1 week agoNice but small
I purchased the full-size mask and also received a deluxe sample of the Leave-In Molecular Repair Hair Mask. Because I own the full size, I can say that the product does help — I do see positive results in my hair. It feels smoother and healthier with consistent use.
That said, the sample itself is only enough for one application, so if someone is trying it for the first time, one use is really not enough to decide whether it’s a must-have or not.
My main concern is the value. The mask works nicely, but it gets used up very quickly. Realistically, you need at least three pumps per use, and the bottle is only 100 ml, so it doesn’t last long.
It’s also frustrating that larger, more affordable sizes are only available to licensed hairdressers. As a regular customer, you’re stuck paying the premium price, which honestly feels limiting and a bit unfair.
Overall, it’s a good product with visible benefits, but I’m still unsure if it’s truly worth the price for the amount you get.
KK18Hair1 week agoThank you so much for your detailed and honest feedback — we truly appreciate you sharing your experience. We’re so glad to hear you’re seeing smoother, healthier results with consistent use. That’s exactly what we hope for.
With K18, less really is more. Because the formula is highly concentrated, most clients only need 1–3 pumps total, depending on hair length, thickness, and density. For many hair types, starting with 1 pump and adding more only if needed is key. Using more than necessary won’t improve results and can cause you to go through the product more quickly than intended. We also understand your concerns about value and sizing. We truly appreciate your perspective and your continued support. If you’d ever like personalized guidance on usage amounts based on your specific hair type, we’re happy to help.
