K18 Leave-In Molecular Repair Hair Mask

You’ve likely seen or heard of the K18 Leave-In Molecular Hair Repair Hair Mask by now. It’s become quite the cult favorite quickly. I’ve had quite a few changing thoughts about it as I keep playing with it so I really wanted to finish a full bottle and try it every way I could think of before talking about it. So essentially this is a 4 minute leave in treatment to reverse hair damage. I color my hair regularly so it sounded great for me. Plus there have been so many glorious reviews flooding the internet about it. I first saw it about a year ago in the New Beauty magazine then it kind of took over the internet after that. Details per K18 site:

A leave-in treatment mask for all hair types that clinically reverses damage in 4 minutes. The patented peptide technology works to repair damage from bleach, color, chemical services & heat – restoring strength, softness, smoothness, and bounce to hair.

Traveling deeper into the inner layers of hair than traditional repair products, our revolutionary patented K18Peptide™ is just the right size and makeup to fit in and reconnect broken keratin chains, renewing hair with strength, softness, smoothness, and bounce. You can feel and see the difference with the first use.

See dosage chart for exact usage. For best results, use for the first 4-6 consecutive washes, then every 3-4 washes as needed to maintain hair strength.

This product has quite a few very specific instructions so I will lay out what they tell you to do from their site first…

Directions:

So first off this is a 50ml product that retails for $75. It’s not cheap. It comes in an airless pump. The product is white and has a kind of creamy typical leave in hair cream feel. The scent is a lighter floral perfume scent, it’s not too strong or overpowering. How does this work? Well hair is made up of tons of polypeptide keratin chains. When you damage your hair the inner keratin chains get weak and break. This damage causes the hair to loose elasticity and strength resulting in loss of resilience and shine aka “healthy looking hair”. Their patented peptide supposedly brings back damaged hair to its original state. It’s supposed to go in and help reconnect those broken inner keratin chains. You also should start to see results after one use according to the brand. So that’s the basics of how it works and it would be ideal for anyone looking to bring back their hair to a healthier state. Who doesn’t want that right? No one.

So I color my hair and typically I’m the type that should see the most visible improvements per the brand. If you have healthy hair you might see less improvements as you have less to gain. Kind of like anti-aging products. The more to gain the more you’ll see. I most definitely have a love/hate relationship with this product and I’ll explain why. So at first you have to use this 4-6 shampoos in a row. I decided to go with 6 in a row to get the full results. I shampoo 3x a week so that’s two weeks only using shampoo and this K18 product. I abided by all the rules, no conditioner, use a clarifying shampoo, don’t use anything for 4 minutes after applying, towel dry first and don’t use too much. When I had really long hair I used 2.5 pumps and now with mid length hair I use 2 pumps.

I’ll give you a little background about how I style my hair so you understand where my love/hate comes from. I brush my hair well before getting in the shower, shampoo and use conditioner (quite a bit my hair is dry) in the shower then use a drying towel like Aquis. I do not comb my hair at all after the shower, I scrunch and apply a wave spray and a light conditioning mist possibly with a hair oil or cream leave in on the ends only (helps hold the waves longer) and I air dry, I never use a blow dryer or heat on my hair. One I don’t have the time in the morning and two air drying really is the only thing that brings out my waves really well. If I comb or dry my hair with heat in any way after the shower my hair goes straight and I loose the natural wave.

I bring all this up as it’s important because using K18 makes me not be able to use this method for styling my hair. Below is a photo of me after using K18 with my usual styling method as listed above. I did not comb it after applying K18. So K18 ruined my waves making them very weak (I have way better waves with normal conditioner) and also it made my hair feel heavy and almost dirty. It looked dull and matte, not the usual shine I get from conditioner. I pretty much put it up shortly after it dried that day. This was wash number two in a row. The next day my hair felt greasy and heavy like I needed to shower again and I’m normally totally OK with 3x a week for washing. I endured four more washes in a row after this all with the same effect. Honestly I almost quit K18 after 6 in a row. I just hated how it made my hair feel texture wise. It ruined two days of hair for me that I just wore it in a ponytail then I was basically washing and doing the same thing again. This lasted for two weeks. I wore a ponytail for two weeks solid. I didn’t get that shiny look or more curl expression like other friends I had seen online getting (some say it really helps express their curls and make them more prominent which is something I was hoping for).

I still continued to try it about every fourth wash after. So you initially go through the 4-6 washes in a row then just use K18 once every 3-4 washes. I tried varying ways of styling to see what worked. I found combing my hair after applying K18 took away the frizzy matte look and gave my hair a more tolerable almost sleek look. It did ruin any waves whatsoever I had and makes my hair straight. So it still goes in a ponytail on K18 days but it looks better. I’ve even been experimenting with using no extra leave in conditioners or styling products on K18 days. This seems to be the best for me. It helps reduce that heavy feel the next day. No matter what I try I cannot style my hair like normal on K18 days, it’s strictly a ponytail day 100% of the time. So I plan for that now. Weekends, if you remember, are great for this product if you’re not doing anything.

So after sticking through a full bottle (I just cracked open bottle two a few weeks ago) I have noticed my hair looks sleeker when I use it compared to before, less of that matte feel. It seems to be helping more as a cumulative effect, or maybe I just had so much damage to repair it took a while to reach this stage? I love the day I wash my hair after using K18. It looks great that day when done in my normal styling fashion. I feel there are definitely benefits to using it. Now that I’ve gotten past the initial phase my hair does feel healthier. I’m not saying it doesn’t have benefits at all–It does. There’s just something about the day I have to use K18 as it ruins a good hair wash day because I loose my waves and have to put it up. I only get 3-4 good air dry wave hair days a week as it is so it takes one away from me. That’s part of my issue with it. I don’t like that I can’t style like normal when using it. This is a very personal thing because for many it won’t affect how you style your hair.

On the other hand, I do like what it seems to be doing after a few months of use. So hence the love/hate relationship. I’ve found that the longer I continue using K18 the more benefits I see. It does also seem to loose the gross feeling the longer I use it. It used to leave this grainy greasy film on my hair for 24 hours after applying but now it’s more like 8 hours then it feels shiny and normal again. Honestly I think this product is great for anyone who brushes or combs their hair after washing, likes a straight hair look, or if you blow dry your hair and then style with a curling iron or flat iron or whatever. I can see how this would make your hair look sleek and healthy. If you don’t like to comb your hair after a shower because of curls or waves you may not like this as much as others do. There’s something about how conditioner in the shower acts like a natural brush making it easy to not comb after, you loose that effect with this.

I think this product will be very personal for many people. Either you will love it and not mind the process or it may drive you nuts. I’ve heard some tell me they had a lot of issues with it as well. Some have told me they only use it once a month which would actually be totally doable if that works for you. Bad hair day once a month for healthier hair in general–I can do that. I think it’s just the loss of a once a week good hair day that has me more irritated while using it. Now I could blow dry and curl my hair those days but I’m far too lazy for that and don’t have the time, that’s why I switched to air dry anyway. I use the air dry method for my hair because it’s quick and simple with effects I like. Now sometimes when I post I dislike the product in my Instagram stories I get a lot of upset people because they all love it, many tell me I’m using it wrong. I’ve used it every way possible–trust me. I’ve used with with and without many combos of other leave in styling product versus just K18, I’ve used 1, 1.5, 2, 2.5 and 3 pumps just to see, I’ve brushed after or not brushed after, I always follow their do’s and don’ts especially using after a clarifying conditioner every time. Sometimes products just don’t work the same for everyone and the way you style your hair will play huge into this product and how you like it.

I’m glad I gave it a longer chance as it seems to have taken some time to work better for me. So for me the best way is no extra products after, comb it after use, 2 pumps. Ruins my waves but it does seem to be increasing the resilience and healthy feel of my hair overall. I still dislike the days I use it but the benefits outweigh the issues for now. If you blow dry or have straight hair that you tend to curl or style after a blow dry I think you will be a target person for this product. It’ll work well for you. I’ll finish bottle number two then decide if I continue longer. Once you seem to make it through the beginning phase (which lasted way longer than 6 washes) it seems to be better. Keep in mind less is more as well. 2-2.5 pumps should work for most people with 4 being on the high end. It can get greasy the more you use, this is one where less is more. Have you tried K18? Thoughts? I got mine off Lovelyskin.com at first but it’s now available on Sephora as well.

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.