professional molecular repair mask
Second step of K18REPAIR™ service reverses damage post-service
Made to be used as part of the K18REPAIR™ service (K18 PRO mist + K18 PRO mask)
This leave-in treatment mask repairs hair damage and restores hair to a healthy state after salon services. Powered by the K18PEPTIDE™ to reconnect broken polypeptide chains and disulfide bonds to renew strength and elasticity in just 4 minutes. This mask is clinically proven to repair damage from bleach* + color*, chemical services*, and heat* for immediate + lasting results. Cream-based format helps soften, smooth, and condition hair.
Bleach + Color
Heat
Chemical Services
more to know
Takes damage repair further – biomimetic peptide seamlessly fits in and reconnects broken polypeptide chains at the molecular level. As a result, disulfide bonds are also reconnected for reinforced strength along the length + width of hair—offering comprehensive, lasting repair
Restores hair before and after color and chemical services by working at the innermost layer of the hair, core strength and elasticity are renewed for strong, smooth, bouncy hair
Delivers immediate and lasting results – hair is repaired from the first use and lasts past your next wash, for ongoing reparative benefits
Works on all hair types – because K18PEPTIDE™ works on a molecular level (where all hair is the same), this product is effective on all hair types and with every service
Clinically proven to reverse hair damage – from: bleach + color, chemical services, and heat
key benefits
- K18PEPTIDE™ is a biotech-developed peptide that mimics hair's structure to reverse damage by reconnecting polypeptide chains and disulfide bonds broken during bleach, color and chemical services, and heat*.
- pH-optimized (5.0-6.0) to help minimize cuticle swelling + put hair proteins in their most resilient state after salon service or shampoo
- Cream format enables easy, lightweight application across all hair types, with detangling and softening benefits.
- Vegan, color-safe, cruelty-free
how to use
The K18 professional molecular repair hair mask is meant to be used as the second part of the K18REPAIR™ service.
With a color or chemical service:
- Before the service, apply K18 professional molecular repair hair mist. Wait 4 minutes. Do not rinse out.
- Apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots. Let sit for 4 minutes. Do not rinse out.
- Proceed with cut or style as usual.
- If toning, use K18 PRO mist first, wait 4 minutes, then apply toner directly over PRO mist. Process as usual. Rinse or shampoo toner + apply K18 PRO mask per instructions above.
Without a chemical service:
- Shampoo, do not condition. Towel-dry thoroughly
- Apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots.
- Let sit for 4 minutes. Do not rinse out.
- Proceed with cut or style as usual.
ingredients
Water (Aqua) (Eau), Alcohol Denat., Propylene Glycol, Cetearyl Alcohol, Dicaprylyl Ether, Cetyl Esters, Behentrimonium Chloride, Polysorbate 20, sh- Oligopeptide-78, Hydrolyzed Wheat Protein, Hydrolyzed Wheat Starch, Isopropyl Alcohol, Tocopherol, Phenoxyethanol, Potassium Sorbate, Citric Acid, Fragrance (Parfum), Geraniol, Linalool, Hexyl Cinnamal, Benzyl Alcohol, Amyl Salicylate, Benzaldehyde.

still have questions? visit our help center
who is it for?
K18 is engineered to work with every hair type, in every service, and with every routine.
why skip conditioner?
Traditional conditioners leave a film on hair that blocks our peptide from penetrating effectively. Once the 4-minute wait time is up, feel free to use a conditioner, a leave-in, or any type of styling product.
does K18 mask replace conditioner?
Think of the K18 mask as a highly concentrated treatment. It restores hair’s strength + elasticity in the innermost layers of hair, instead of traditional conditioners that coat the outside of hair. After the 4-minute wait time post-K18 mask, feel free to add a leave-in for a boost of conditioning if needed.
Is the K18 pro mask and take-home mask the same?
Yes, both formulas are the same. The PRO mask is conveniently sized for PRO use.
Repair damage for hair like new* in 4 minutes.
Biomimetic peptide clicks into hair’s keratin structure—the source of core strength—for soft, shiny, bouncy results that won’t wash away.
2. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes (do not rinse out).
4. If needed, dry the hair prior to applying lightener or color. Then perform your desired technique.
5. Process your lightener or color as usual, then rinse and shampoo with K18 PEPTIDE PREP™ detox shampoo. Do not condition.
6. Apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots.
7. Wait 4 minutes (do not rinse), then apply 1-3 drops of K18 molecular repair hair oil to mid-lengths and ends.
8. Wait 4 minutes, then proceed with cut or style as usual.
9. Add an additional 1-3 drops of K18 molecular repair hair oil to dry hair as a finisher.
Please see the “K18 + toning or glossing” section for more information on toning with K18.
2. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist per quadrant, increasing up to 20 sprays as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes (do not rinse), then apply toner or gloss.
4. Process toner or gloss as usual, then rinse. If shampooing, follow with K18 PEPTIDE PREP™ pH maintenance shampoo. Do not condition.
5. Towel dry hair, then apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots.
6. Wait 4 minutes, then apply 1-3 drops of K18 molecular repair hair oil to mid-lengths and ends.
7. Wait 4 minutes, then proceed with cut or style as usual.
8. Add an additional 1-3 drops of K18 molecular repair hair oil to dry hair as a finisher.
2. Towel dry hair, section hair into 4 quadrants, then apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes (do not rinse), then wrap, process, and neutralize perm as usual.
4. Once perm is complete, remove rods and gently towel dry.
5. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist per quadrant, increasing up to 20 sprays as needed, depending on client’s length, density, or level of damage.
6. Wait 4 minutes (do not rinse), then proceed with cut or style as usual.
To avoid weighing down fresh curls, it is not recommended to use the K18 professional molecular repair hair mask or oil immediately after completing a perm service.
2. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes (do not rinse out) and if needed, dry the hair prior to beginning relaxer application.
4. Apply + process relaxer as usual, then rinse thoroughly.
5. Towel dry hair, then re-apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, and level of damage.
6. Wait 4 minutes (do not rinse), then follow with neutralizing shampoo. Do not condition.
7. Towel dry thoroughly, then re-apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots.
8. Wait 4 minutes (do not rinse), then apply 1-3 drops of K18 DAMAGE SHIELD protective conditioner from mid-lengths to ends. Build as needed.
9. Rinse thoroughly, then towel dry hair and apply 1-3 drops of K18 molecular repair hair oil to mid-lengths and ends.
10. Wait 4 minutes, then proceed with cut or style as usual.
11. Add an additional 1-3 drops of K18 molecular repair hair oil to dry hair as a finisher.
2. Towel dry hair, then apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes, then apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, starting at the ends and working up towards the roots.
4. Wait 4 minutes, then apply 1-3 drops of K18 molecular repair hair oil to mid-lengths and ends.
5. Wait 4 minutes, then style as usual.
6. Add an additional 1-3 drops of K18 molecular repair hair oil to dry hair as a finisher.
2. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes (do not rinse out). Then follow with the recommended shampoo per your keratin straightener service instructions.
4. Apply and process keratin straightener as usual.
5. Apply 1-3 drops of K18 molecular repair hair oil to mid-lengths and ends on dry hair as a finisher.
Wait 3-4 shampoos post-treatment before using the K18 molecular repair hair mask in the salon or at home.
1. Section dry hair into 4 quadrants.
2. Apply a minimum of 10 full sprays of K18 professional molecular repair hair mist to each quadrant, increasing up to 20 sprays per quadrant as needed, depending on client’s length, density, or level of damage.
3. Wait 4 minutes, then rinse and shampoo with K18 PEPTIDE PREP™ detox shampoo (do not condition)
4. Towel dry hair, then apply 1-3 pumps of K18 professional molecular repair hair mask based on your client’s length and density, only to the ends and mid-lengths (avoiding the root).
5. Wait 4 minutes (do not rinse), then proceed with extension installation as usual.
Using K18 on extensions alone or on clients with previously installed extensions:
K18 is suitable for use on all human hair extensions (to include tape-in, k-tip, hand tied, clip-in, sew-in, etc.). For information on using K18 on clients with previously installed extensions, please follow the instructions for the specific service being performed.
PRO tip: When working on clients with tape-in extensions, we recommend following the standard protocol for cream-based conditioner or oil usage. For best results, do not apply the K18 professional molecular repair hair mask or molecular repair hair oil directly to the weft adhesive or to the natural hair immediately surrounding the adhesive as it could cause slippage.
See how K18 unlocks our community's expression
- Hair Texture
- Hair Damage
- Effectiveness
- Hair Repair
- Shine
- JordanReviewingFull-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)I recommend this productAge 18 - 24Hair Concern Heat damage, Fragile/brittle hair, Frizz, Color-care, Chemical damageHair Type Curly/CoilyMy Results Stronger Hair, Bouncy Hair, Visible Difference, Smoother Hair, Cleaner, fresher hairRated 5 out of 5 stars4 days agoLoveee
My hair was so damaged after using it twice my curls came back n
Was this helpful?K18Hair PRO4 days agoThank you so much for the love! 💙 We're thrilled to hear you're loving the Full-Size Leave-In Molecular Repair Hair Mask and seeing such amazing results with your curls! ✨
- Julie o.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)I recommend this productAge 25 - 34Hair Concern Color-care, Heat damage, Chemical damageHair Type Thick/CoarseMy Results Less Breakage, Shinier Hair, Soft Touchable Hair, Cleaner, fresher hair, Stronger HairRated 5 out of 5 stars6 days agoA must have for color treated hair!
I’ve been using K18 for about two years now, and it has made such a difference in the health of my hair! I color my hair frequently and have it professionally done, and K18 keeps it feeling soft, strong, and healthy despite all the processing. It’s become a must-have in my haircare routine, and I highly recommend it!
Was this helpful?K18Hair PRO6 days agoThank you so much for the love, Julie! 💙 We're thrilled to hear K18 has become a must-have in your routine. Your loyalty means everything to us! ✨
- Zoe P.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)I recommend this productAge 35 - 44Hair Concern Color-care, Fragile/brittle hair, Frizz, Split-Ends, Extending time between washesHair Type Thick/Coarse, Straight/WavyMy Results Less Frizz, Bouncy Hair, Visible Difference, Stronger Hair, Less BreakageRated 5 out of 5 stars1 week agoAmazing
Has absolutely changed my hair for the better!!! I have bleached hair and honestly I have felt and seen a difference after one time, it’s very easy and has made my hair care routine a lot easier !!!! The photos speak for themselves
Was this helpful?K18Hair PRO1 week agoThank you so much for the love, Zoe! 💙 We're thrilled to hear the Full-Size Leave-In Molecular Repair Hair Mask has transformed your bleached hair! ✨
- Hailey S.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)I recommend this productAge 25 - 34Hair Concern Heat damage, Chemical damage, Fragile/brittle hairHair Type Thick/CoarseMy Results Less Breakage, Shinier Hair, Smoother Hair, Less FrizzRated 4 out of 5 stars1 week agoHair color treatment
My hair is always difficult to color/bleach because of my hair porosity but since doing the k18 treatment I had no issues!
Was this helpful?K18Hair PRO1 week agoThank you so much for the love! 💙 We're thrilled to hear the K18 Leave-In Molecular Repair Hair Mask is working beautifully for your hair! ✨
- Marisol M.Verified BuyerReviewingFull-Size Leave-In Molecular Repair Hair Mask 50 mL (WHOLESALE)I recommend this productAge 25 - 34Hair Concern Heat damage, Chemical damage, Dryness, Color-care, FrizzHair Type Fine/ThinMy Results Less Frizz, Visible Difference, Stronger Hair, Less BreakageRated 5 out of 5 stars1 week agoYou must try it!
I’ve been using K18 for a few weeks and I’m honestly impressed! My hair feels so much softer, healthier, and less dry. I have color-treated hair, and I can definitely see a difference, especially on my ends. A little pricey, but totally worth it for me!
Was this helpful?K18Hair PRO1 week agoThank you so much for the 5-star review, Marisol! We're thrilled to hear you're loving the results on your color-treated hair. 💙 We truly appreciate your support! ✨




