Like most things, hair comes in all shapes and sizes. Some have ultra-fine hair, some thick, some curly, and some pretty damaged. The thing that might unite all hair types is that we have definitely all had a bad hair day.

With that in mind, K18created a universal fix to bring bounce back to all hair types at the molecular level: their Leave-In Molecular Repair Hair Mask.

K18's unique, science-backed approach to haircare actually works. The K18Peptide™ is clinically proven to repair strands from the inside reversing damage to create healthier, stronger hair.

While there are plenty of hair masks on the market, K18's new category offers something different for haircare: visible results and a turnaround time of 4 minutes.

Here's what three women with all different hair types had to say about K18:

Finer Than Fine Hair

Favorite Feature: Strengthens hair

Experience: I have extremely thin hair. The kind of thin hair that breaks when I brush it, comes out in the shower, and somehow even breaks when I sleep.

I was in an endless cycle of trying to give my hair volume by blow-drying it and was ultimately left with frizzy, heat-damaged hair. Even using a thickening conditioner felt like too much product for my hair and gave it a greasy look.

K18completely changed that. I was so self-conscious about all the breakage my hair had gone through, but K18 went to work on every single strand and left me with stronger and frizz-free hair.

Even though my hair is naturally thin, I'm no longer losing or breaking any hair while styling —hot tools and ponytails are finally a safe option! K18 has given me so much confidence with their leave-in mask, I can't imagine my hair care without it.

Double The Damage

Favorite Feature: Knocks years off my hair

Experience: I started greying early, which wasn't ideal but I've learned to work with it. However, between root touch-ups and complete dyes, I am at the salon constantly.

As of late, my hair has started to take notice of how often I visit the salon (and not in a good way). While I'm getting the color I want, my hair is so fried and dried out! It's the definition of color damage.

When my hair stylist recommended K18 to bring my hair back to life, I was a bit hesitant. My hair care routine had been the same for ages, but she insisted that this was the renewal my hair was craving, so I gave it a shot. After just one wash, I noticed my hair starting to get some of that shine and thickness back to it.

Now I can dye my hair to get the color I want without worrying over the harm it's causing. Using K18means that I don't have to settle for dull, dry hair anymore. One at-home treatment brings my hair right back to life and it's a youthful, healthy state that I haven't seen in years.

Keeping My Curls

Favorite Feature: Results in just four minutes!

Experience: Having naturally curly hair is great, but it's a lot of maintenance. I spend hours in the bathroom for my wash routine, detangling process, and applying product after product to control my frizz.

It takes upwards of thirty minutes for me to feel like I've really worked enough product into my hair because it's so thick. Another friend in the curl community recommended I check out K18 and since they've never steered me wrong before, I decided to give it a shot.

Wow, they were right! K18 is the answer. This Hair Mask is the easiest product I've ever used. After I shampoo my hair, I skip the conditioner and towel dry. Next, I use two pumps of K18, leave-in for four minutes, and then go about my styling for the day. Not only is my frizz under control, my curls still have their bounce, and I don't have to add more time to my hair care.

I've used a lot of masks, but none have actually been able to tame my hair like K18's Leave-In Molecular Repair Hair Mask. My hair is softer, smoother, and infinitely more manageable to style.

Final Thoughts:

K18's formula is legendary. While taking conditioner out of the equation might feel foreign, the four minutes spent with K18 does more for hair than five years of conditioning ever could.

No matter what type of hair, K18offers next-level renewal. Check out the Leave-In Molecular Repair Hair Mask and see your hair come back stronger than ever.