K18, formerly known as KhairPep and one of the latest products in hair bonding technology, is a reparative leave-in treatment that claims to reverse hair damage from lightening and chemical services, mechanical damage and heat, bringing hair back to its youthful state.

There are two lines of K18, one for professional use and one for home use. The in-salon service includes a mist that is applied before color service and the mask after the service. The same mask in a smaller size is for home use.

Ingredients: Water (Aqua) (Eau), Alcohol Denat., Propylene Glycol, Cetearyl Alcohol, Dicaprylyl Ether, Cetyl Esters, Behentrimonium Chloride, Polysorbate 20,sh-Oligopeptide-78 (K18Peptide™), Hydrolyzed Wheat Protein, Hydrolyzed Wheat Starch, Isopropyl Alcohol, Tocopherol, Phenoxyethanol, Potassium Sorbate, Citric Acid, Fragrance (Parfum), Geraniol, Linalool, Hexyl Cinnamal, Benzyl Alcohol

The K18 hair mask is not a protein or conditioning treatment, but does contain small amounts of protein and behentrimonium chloride that has conditioning and smoothing properties. From the K18 website, “the K18Peptide shuttles amino acids (the building blocks of hair) into the inner structure of the hair. Once inside the hair cortex, the unique amino-acid chain goes directly to the broken disulfide bonds to replace the lost amino acids, regenerating the bond and restoring ultimate strength, resilience and softness.” This contains denatured alcohol, benzyl alcohol and isopropyl alcohol that allows the product to penetrate deeper into the hair.

Directions: Before the first use, wash with a clarifying shampoo. Shampoo hair; do not condition. Towel dry hair. Start with one pump and add more as needed depending on length and thickness. Work evenly through hair from roots to ends. Let sit 4 minutes. Do not rinse. Add styling products if desired and style as usual. Use for 4 to 6 consecutive washes and then every 3 to 4 washes for maintenance.

For about a month before I started using the K18 hair mask, my hair had been breaking, very small pieces from the front hairline (while combing or even just fluffing it up) and long pieces from the back hairline. The breakage from the back was similar to when I had blonde hair and when finger combing conditioner (or using “prayer hands”) through the hair, I was left with almost a handful of thick strings of hair such that I would get rather nervous on wash day and as a result my hair feels shorter and thinner at the ends when putting it in a ponytail. My hair does not seem to break off when combing before washing (other than the very small pieces), only while conditioning. I got the K18 mask hoping this would be a solution. I should mention too that it has been just over 2 years since I have had a haircut and hair that has not been cut for so long can split and break.

I have thin hair that has not been colored or cut in 2 years and I rarely use heat. I used the K18 mask for six consecutive washes, using a clarifying shampoo the first wash. I towel dried the hair, parted my hair in two sections and used one pump on each section, let it sit for 4 minutes, applied a leave-conditioner (I still use this one) and air dried as usual.

The K18 hair mask is 75 USD/89 CAD for 50 mL. I got my mask from coastalbeauty.ca at 75 CAD. One pump is 1 mL, so I get 25 uses applying two pumps each use.

K18 is a medium-thick cream that has a sort of fake fruity scent like other salon products. While shampooing, my hair does not get too tangled and it is thin, so applying the K18 mask worked relatively well to detangle. When I was figuring out how many pumps to use, I first used one too many and my hair felt heavy and sticky after air drying. Using two pumps was better; the hair had movement, no residue and more body than usual (perhaps because conditioner is not used).

Above shows before using K18, after six consecutive K18 uses and after normal shampooing and conditioning. I noticed a difference in the feeling of my hair by about the fourth consecutive use. My hair is usually quite frizzy and feels a bit rough and dry and after the strands of hair felt much smoother and the ends felt less dry.

Comparing Olaplex No. 8 and K18, I do not see too much difference in the hair; it looks smoother and less frizzy. After K18, my hair feels much smoother than the Olaplex Intense Moisture Mask that provides a similar function (I have used the No. 3 and No. 8; not sure which would be more comparable) to repair, strengthen and smooth damaged hair. I will note that when I went blonde, my hairdresser used Olaplex during the service and a while later I used the Olaplex No. 3 hoping to repair some damage; my hair could not be saved (not to say Olaplex does not work of course). From the Luxe Color Lounge website, “K18 is great if you are dealing with damage from heat styling, while Olaplex is more for bleached hair.  The Olaplex method uses fake bonds, and you can reach a point where you are using it so often that your hair becomes so strong that it breaks. Because Olaplex is not a natural protein, when you stop using it, your hair can no longer hold on to it, therefore it falls out reverting your hair back to its previous structure.” With K18, however, as I have seen on Instagram, hairdressers are using it during lightening and color services and seeing much improvement in the quality and strength of the hair. From the K18 website, with one salon treatment using the mist and mask as part of the bleaching service, hair is restored to 91% its original strength and 94% its original elasticity. K18 apparently rebuilds keratin bonds permanently, and is not a rinse-out treatment like Olaplex.

Since K18 claims that the mask restores hair to a youthful state, I wanted to compare from 2018 when my hair was the healthiest it felt and looked in a long while. Not sure it is quite a fair comparison as in my case, hair, lifestyle and stress have changed over time; I have more greys, my hair is drier and frizzier, diet and exercise habits are not where they should be compared to 3 years ago and stress has greatly increased over the last months to year.

As for the breakage of long pieces of hair, while finger combing the K18 mask through, I had hair fall, however, not the breakage I was getting while conditioning my hair. After the 6 uses of K18, I shampooed and conditioned my hair as normal and was quite worried, however, I just got my typical hair fall and was not pulling out broken hair. K18 stopped my hair breakage?! I continued with the my normal wash routine four times (still no broken hair) and then used the K18 mask. This time while finger combing the mask through, I pulled out strands of broken hair; not as much as before using the mask.

I think the K18 Molecular Repair Hair Mask is good; I kind of expected my hair to look better though. It does not really look much different, but feels really smooth; K18 seemed to repair my hair so there was no breakage for a few washes and then less breakage than I was getting previously. For the tiny pieces that were breaking, instead of seeing six pieces after combing my hair, I was getting 1 or 2. I will hopefully get my hair cut soon and have enough of the K18 mask to provide an update here. When I get my hair lightened/colored (likely not for a while), I will be looking for a salon that uses K18 and will update again.

Update (January 3, 2022): I finally got my hair cut at the beginning of November and have used K18 a couple times since then. I have not noticed further improvement in using the K18 mask, but my hair really needed a cut; I have had no further breakage and my hair looks and feels much better (update to my hair story here). I will be getting my hair lightened and colored (a balayage and/or color melt) in about 3 weeks. The salon I am going to does not use K18, but I will use my hair mask at home and update at that time.

Update (February 21, 2022): My regular hairdresser no longer works weekends nor later in the evenings, so I am currently looking for a new salon; a color/K18 update will likely be posted in the summer.

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