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23,434
4.3 out of 5 stars

K18 Leave-In Molecular Hair Mask, 1.7 oz

$45.99
$71.25 35% off Reference Price
Condition: New
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Top positive review
11 people found this helpful
I was skeptical, but it did what it promised!
By Sarah Frost on Reviewed in the United States on May 28, 2025
I don't usually review these kinds of products, because I never see the “miracle results” they rave about. My hair is bleached, damaged and fried at the ends and I was hoping to find something to save at least a few inches of it, so that I wouldn’t have to chop a ton of it off. I swore by the gold standard of Olaplex no. 3 and used it every week for hours at a time, even sleeping with it in, but it only had modest results. This product seemed way overpriced and the instructions too good to be true…just leave it on for four minutes and that’s somehow enough time to work? No conditioner after? But I finally bought the small bottle and tried it. It is TINY and I have long hair and can maybe get two uses out of the bottle, but it did WAY more for my hair than Olaplex! In fact, I got better results from this tiny little bottle than I did from several months of 30$ Olaplex bottles, so this saved me money. Last night I showered, blotted my hair dry thoroughly with a towel, then combed the product through and waited, before applying a spray leave-in conditioner just in case. I blow-dried it with protectant gel in and styled it as usual. It looked much better immediately after. Today I woke up and my ends are AMAZING. They’re not virgin hair by any means, but they finally look much softer and healthier, not bleach-damaged! All my hair feels much softer and looks shinier. Frankly I’m stunned this actually worked so well, and immediately came back to buy the bigger bottle. If continuing to use it produces even more results, my hair will go from bleachy damaged mess, to soft and amazing, and I couldn’t be happier. It’s expensive as heck, but WORTH IT. If you have damaged, bleached hair, buy this.
Top critical review
3 people found this helpful
Had Higher Hopes
By Elizabeth Hernandez on Reviewed in the United States on May 27, 2025
I had high hopes for the K18 Leave-In Molecular Hair Mask, especially with all the hype surrounding it. While I appreciate the science behind it, I was honestly expecting a bigger bottle for the price, it’s definitely on the pricey side for the amount you get. After using it several times, I haven’t noticed much of a difference in the texture or health of my hair. It didn’t make it worse, but it also didn’t deliver the noticeable results I was hoping for. Maybe it works better for some hair types, but for me, it just didn’t live up to the promise.

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