K18 Hair Mask Review – 3 Months Before & After Results

If you purchase an independently reviewed product or service through a link on our website, WWD may receive an affiliate commission.

Truly effective products are needed to reach holy grail status within a few years. K18’s Leave-In Molecular Repair Hair Mask does just that, emerging in late 2020 as the bond-builder’s new “it” girl.

This mask acts as a leave-in treatment and is designed to reverse bleach, color, chemical, and heat damage in 4 minutes. Contains K18 peptide, a unique biomimetic component that reconnects broken polypeptide chains and disulfide bonds. In non-scientific terms, this treatment will make your hair look great very quickly.

K18 Leave-In Molecular Repair Hair Mask works a little differently than the OG bond builder, Olaplex. K18’s peptides bind to and repair damaged keratin proteins, while Olaplex focuses on forming new bonds, so you can combine the two if needed. Technically speaking, K18 repairs damage more deeply, but both can help improve hair quality.

In addition to the repair benefits of the K18 leave-in hair mask, it also speeds up your daily routine because you don’t have to apply conditioner after shampooing or stiffen your hair before getting out of the shower and rinsing. It may seem counterintuitive to skip the conditioner, but this actually allows the mask to penetrate the hair shaft more effectively. After waiting 4 minutes, you can apply additional leave-in conditioner or hair styling products if desired.

Our beauty writer was introduced to the K18 Molecular Repair Hair Mask in 2022 and has been using it religiously ever since. Read her honest and unbiased review and see her impressive before and after photos.

register to WWD shop newsletter Get the scoop on the best in beauty and style with in-depth reviews of exciting new releases and a buyer’s guide to finding the products you need to try ASAP.

How to test K18 hair mask

K18 Hair Mask Review — Test Notes

Tldr; K18’s non-rinse hair mask is actually Magic in a bottle.

As a seasoned beauty industry reporter, I’m usually wary of anything with claims that sound too good to be true, but K18 really lives up to the hype. This brand’s Leave-In Molecular Repair Hair Mask literally saved my hair after a manic coloring session during the COVID-19 era. Not-so-fun fact: Years of beauty expertise can go out the window during a mental health episode. Since then, I’ve discovered mood stabilizers and K18, and my hair and I I’m much healthier now.

Two years ago, I tested a K18 hair mask for the first time after being recommended to it by a celebrity colorist. Rachel Bottthe person who did my hair before coronavirus has kept me out of the salon. (So ​​does Rachel. beyonce hairso I would like to let her run her own life. )

Before using K18, my color was changing as quickly as my mood. It went from bright red to pastel pink in a few months, during which time I bleached it with minimal damage. I used demi-permanent color for the red and color deposit conditioner for the pink. Both faded gradually and didn’t require much lifting along the way.

It wasn’t until I tried a “ginger” colored conditioner that things really got worse. As I expected, the shade was more orange than copper, but I decided to give it a try. I thought it would just fade out like the rest of my work, but I was so wrong. My hair cuticles were dirtier than I’ve ever seen them in all my years of testing hair products. (After all, I was just one of them) many victims About ginger stain. )

I bleached it again in a desperate attempt to get rid of the orange, but it didn’t remove much of the pigment. Next, I tried Color Oops Hair Color Remover, dandruff shampoo, dish soap, and every other dye remover I could think of. (Pro tip: Run do not have The orange color disappeared after about 3 weeks, but my hair was completely frizzy, extremely porous, and completely dehydrated. When it got wet, it turned to mud. My natural waves are gone, replaced by a frizzy, fried texture. My cuticles were rough and my hair was swollen, making it look comically voluminous. Some parts were also starting to break. Not my best look.

Since I started using K18, the damage has been repaired incredibly quickly. After just one treatment, my straw-like hair looked smoother and shinier. One! So “heals damage in 4 minutes” was no joke. I was immediately hooked.

Technically, you only need to use it 4-6 times as needed after your salon service. Well, I necessary So I used it every day for the first month. During that time, I noticed a significant improvement in both the strength and softness of my hair.

After the first month, I got some highlights to get rid of the harsh root lines instead of having to treat them twice like I used to. I decided to use K18 twice a week for the next two months. At that point, my hair had completely changed, even though I had undergone additional chemical treatments.

During the first few months of use, I did not use any other treatments other than K18. I shampooed 4-5 times a week with Prador Gold Label Shampoo and about once a week with Kérastase Blonde Absolute Purple Shampoo for brass protection.

Since then, I stopped bleaching my hair and went back to a more natural red to give my hair a real break. Now that I’m in much better health, I use the K18 a few times a month for maintenance rather than serious damage control. The more you use it, the better your hair will be. The K18 hair mask can get quite expensive if you use it often, but it’s worth every penny in my opinion.

Shop more K18 hair care products

Why trust WWD?

Since 1910, WWD, also known as the “Fashion Bible,” has been the industry’s leading authority voice for senior executives in the global women’s and men’s fashion, retail, and beauty communities, as well as the leading consumer media outlet covering the market. We have also provided information. Today, WWD’s latest news and trend coverage remains a trusted source for fashion professionals and consumers alike. Our shopping editors uphold WWD’s editorial standards and values ​​with expert, high-quality product selections. Learn more about us here.

meet the author

katie mcbroom An award-winning writer and content creator with over 10 years of experience in digital media. Before writing for WWD, she was a content editor at Google and a beauty editor for Hearst’s Best Products. Her work has also appeared in publications such as Cosmopolitan, Elle, Oprah, CNN, Business Insider, and Men’s Health. She is well-versed in all things beauty and is a certified cosmetologist and makeup artist. McBroom has been using the K18 for over two years and wrote this honest review based on her first-hand experience.