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Delivery
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Click & Collect
Free Click and collect is available at checkout. Orders are ready within 1 hour during opening hours. Store Address: 56 Parer Rd, Airport West, VIC Australia 3042 Phone (03) 9999 5902
Limit 1 use. Exclusions apply, including sale items.
K18 Leave-In Molecular Repair Hair Mask is a leave-in treatment that restores damaged hair from within.
This lightweight cream uses advanced peptide technology to travel deep into the hair and reconnect broken keratin chains. Hair feels stronger, smoother, and less brittle, without a heavy or greasy coating.
The texture is silky and spreads easily through damp hair, absorbing quickly with no sticky residue. Once dry, hair feels soft, bouncy, and easier to style, with a natural-looking finish.
It’s ideal for hair stressed by colouring, bleaching, heat styling, or chemical treatments, and perfect before blow-drying or air-drying. With regular use, hair looks more resilient and manageable, so everyday styling feels faster, simpler, and more enjoyable.
How To Use K18 Leave-In Molecular Repair Hair Mask
- Shampoo, then rinse thoroughly. Do not use conditioner.
- Towel-dry hair until it is just damp, not dripping.
- Start with 1–3 pumps, depending on hair length and thickness.
- Apply evenly from mid-lengths to ends, one section at a time.
- Comb through with fingers to distribute. Do not rinse out.
- Wait 4 minutes to let it absorb and activate.
- Style as usual, with or without heat.
- Use after every wash for 4–6 washes, then as needed.
K18 Leave-In Molecular Repair Hair Mask Ingredients
Water (Aqua), Alcohol Denat., Propanediol, Myristyl Alcohol, Cetearyl Alcohol, Behentrimonium Chloride, Amodimethicone, Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate, Cetrimonium Chloride, PPG-3 Benzyl Ether Myristate, Hydrolyzed Wheat Protein, Hydrolyzed Wheat Starch, Cetyl Esters, Fragrance (Parfum), Citric Acid, Potassium Sorbate, Disodium EDTA, C11-15 Pareth-7, Laureth-9, Glycerin, Trideceth-12, Phenoxyethanol, Polyquaternium-37, Hydrolyzed Opuntia Ficus-Indica Flower Extract, Oryza Sativa (Rice) Bran Oil, Argania Spinosa Kernel Oil, Helianthus Annuus (Sunflower) Seed Oil, Rosmarinus Officinalis (Rosemary) Leaf Extract, Tocopherol, Acetic Acid, Sh-Oligopeptide-78 (K18Peptide™).
Note: Please refer to bottle for full ingredients.
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Water (Aqua) SolventsSolvent
Water acts as the main solvent that dissolves and distributes other ingredients in a formula.
May suitAnyone using liquid haircare products, as water is a core component.
Worth knowingIt helps create a workable texture and allows surfactants, conditioners and other actives to perform effectively.
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Alcohol Denat. SolventsSolvent
A fast-evaporating solvent that helps dissolve ingredients and improve product dry time.
May suitPeople who use styling products that benefit from quick drying or a lightweight feel.
Worth knowingIts quick evaporation can help reduce residue and support a clean finish in styling formulas. Some may notice it can feel slightly drying in leave-in products depending on hair type.
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Propanediol HumectantsHydrating humectant
Helps attract and hold moisture in hair and supports a smooth, conditioned feel.
May suitThose wanting lightweight hydration without heaviness.
Worth knowingIt is often used as a gentle alternative to glycol-based humectants and can also help improve product texture and absorption.
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Myristyl Alcohol Conditioning agentsFatty alcohol conditioner
A fatty alcohol that helps soften hair and add a smoother feel while supporting product texture.
May suitThose looking for added slip and softness, especially in conditioners or masks.
Worth knowingFatty alcohols are different from drying alcohols and are commonly used to create rich, creamy textures. They also help formulators stabilise emulsions.
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Cetearyl Alcohol Conditioning agentsFatty alcohol conditioner
A fatty alcohol that helps soften hair and improve the texture of formulations.
May suitPeople looking for smoother, more manageable hair or richer, creamier product textures.
Worth knowingDespite the name, fatty alcohols are moisturising and conditioning rather than drying. They also help stabilise and thicken many haircare formulas.
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Behentrimonium Chloride Conditioning agentsConditioning agent
A conditioning agent that helps detangle and soften, reducing static and roughness.
May suitMost hair types, especially tangle-prone or coarse hair.
Worth knowingA common conditioner ingredient despite the chloride name, which simply describes its chemistry.
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Amodimethicone SiliconesConditioning silicone
A conditioning silicone that targets rougher areas of the hair to smooth and protect.
May suitDamaged, frizz-prone or colour-treated hair wanting targeted smoothing.
Worth knowingDesigned to deposit where hair needs it most. Some prefer silicone-free formulas by choice.
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Pentaerythrityl Tetra-di-t-butyl Hydroxyhydrocinnamate Thickeners and stabilisersAntioxidant stabiliser
An antioxidant that helps stabilise formulas and protect ingredients from degrading over time.
May suitThose interested in product longevity or using heat-styling or UV-exposed products that benefit from stable formulations.
Worth knowingIt is commonly used in many personal care products to help maintain formula quality. It does not affect the feel or performance of the product on hair.
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Cetrimonium Chloride Conditioning agentsConditioning agent
A conditioning agent that helps smooth and soften the hair while reducing static and tangles.
May suitPeople looking for improved manageability, detangling and smoother-feeling hair.
Worth knowingIt is a commonly used quaternary ammonium compound that helps conditioners spread easily through the hair. It is effective even at low levels, which is why it appears frequently in rinse-off products.
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PPG-3 Benzyl Ether Myristate Conditioning agentsEmollient & conditioning agent
Helps soften the hair and improve slip for easier detangling and smoother feel.
May suitPeople looking for smoother, more manageable hair or products with a lightweight, non-greasy emollient.
Worth knowingThis synthetic emollient is commonly used to add spreadability and a silky finish to haircare formulas. It also helps enhance the overall texture of creams and conditioners.
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Hydrolyzed Wheat Protein Proteins and amino acidsProtein
A plant-derived protein that helps smooth and support the hair surface.
May suitHair wanting added body, smoothness or temporary strength.
Worth knowingA common protein in repair and volumising formulas.
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Hydrolysed Wheat Starch Proteins and amino acidsStrengthening and conditioning agent
A hydrolysed plant-derived starch that helps condition and lightly strengthen the hair.
May suitThose looking for added softness, light smoothing or gentle strengthening benefits.
Worth knowingIts smaller molecular size allows it to coat hair more easily than regular starch, offering a softening effect without heaviness. It is commonly used in both rinse-off and leave-in formulations.
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Cetyl Esters Conditioning agentsEmollient / slip enhancer
Provides slip and softness while helping to smooth the hair’s surface.
May suitPeople looking for smoother, more manageable hair textures.
Worth knowingCetyl esters are wax‑like emollients that improve product spreadability and give a soft, conditioned feel. They are commonly used to enhance texture without heaviness.
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Parfum Fragrance ingredientsFragrance
Gives the product its scent.
May suitPeople who enjoy a scented product.
Worth knowingFragrance preference is personal. Some people prefer fragrance-free formulas by choice.
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Citric Acid pH adjusterspH adjuster
Fine-tunes the product pH, which can help the hair surface feel smooth.
May suitMost hair types as part of a balanced formula.
Worth knowingUsually present in small amounts to balance the formula.
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Potassium Sorbate PreservativesPreservative
Helps keep haircare formulas stable by preventing the growth of microbes.
May suitAnyone who uses water-based products that benefit from reliable preservation.
Worth knowingIt is commonly used alongside other preservation systems to maintain product freshness and extend shelf life. It is generally well tolerated in rinse-off and leave-in products.
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Disodium EDTA Chelating agentsChelating agent
Binds to minerals from hard water so the product works consistently and stays stable.
May suitAll products, especially in hard-water areas.
Worth knowingUsed in tiny amounts to keep formulas performing reliably.
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C11-15 Pareth-7 Cleansers / surfactantsNon-ionic surfactant
A non-ionic surfactant that helps cleanse and allows oil and water to mix evenly.
May suitThose looking for effective yet mild cleansing or improved product spreadability.
Worth knowingIt is commonly used in shampoos and styling products to support gentle cleansing and stable formulations. Non-ionic surfactants like this are valued for being versatile in different formula types.
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Laureth-9 Cleansers / surfactantsSurfactant and emulsifier
Laureth-9 helps blend oil and water components and provides light cleansing or solubilising action.
May suitThose looking for products that spread evenly or contain stable blends of oils and water-based ingredients.
Worth knowingIt is a versatile non-ionic surfactant often used at low levels to support product texture and stability. It can also assist with foaming and rinse-off performance.
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Glycerin HumectantsHumectant
Attracts and holds water to help hair feel hydrated and soft.
May suitDry or dehydrated hair, and many curl and moisture routines.
Worth knowingA very common, well-tolerated humectant used across countless products.
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Trideceth-12 Cleansers / surfactantsNonionic surfactant and solubiliser
Helps blend oil‑based and water‑based ingredients and provides gentle cleansing action.
May suitThose using products that need light cleansing or stable blends of oils, silicones, or fragrances.
Worth knowingIt is commonly used to solubilise fragrance or silicone ingredients in shampoos and treatments. Its mild, nonionic nature means it typically works well alongside other surfactants.
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Phenoxyethanol PreservativesPreservative
Helps keep the product stable and pleasant to use after opening.
May suitAll products that need protecting from spoilage.
Worth knowingA very common, well-studied preservative used at low levels.
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Polyquaternium-37 Conditioning agentsFilm-forming conditioner
A conditioning polymer that helps smooth the hair and improve manageability.
May suitThose looking for softer, more manageable hair or extra slip in styling products.
Worth knowingIt forms a lightweight film on the hair to reduce static and enhance glide without leaving heavy residue. It is commonly used in both rinse-off and leave-in formulas.
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Oryza Sativa (Rice) Bran Oil Oils and buttersEmollient oil
A lightweight plant oil that helps condition and soften the hair.
May suitThose seeking added softness, shine, or nourishment without a heavy feel.
Worth knowingRice bran oil is rich in fatty acids and antioxidants, which can support a smooth, conditioned hair feel. It is commonly used in both leave‑in and rinse‑off formulas.
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Argania Spinosa Kernel Oil Oils and buttersConditioning oil
Softens and nourishes the hair, adding slip and a conditioned, glossy feel.
May suitDry, dull or frizz-prone hair.
Worth knowingA popular conditioning oil used across many treatment and shine products.
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Helianthus Annuus (Sunflower) Seed Oil Oils and buttersEmollient oil
A plant-derived oil that helps soften and condition the hair and scalp.
May suitThose seeking lightweight natural oils for moisture, shine or scalp comfort.
Worth knowingIt is rich in fatty acids that support hair softness without feeling overly heavy. Often used as a carrier oil in both rinse-off and leave-in formulas.
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Rosmarinus Officinalis (Rosemary) Leaf Extract Botanical extractsBotanical extract
A plant-derived extract often used to support scalp comfort and provide antioxidant benefits.
May suitThose interested in botanical ingredients or products aimed at maintaining a balanced, refreshed scalp.
Worth knowingRosemary leaf extract is widely used in haircare for its traditional association with invigorating and clarifying properties. It can be included in both everyday and specialised scalp-focused formulas.
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Tocopherol PreservativesAntioxidant
An antioxidant that helps support product stability and can provide conditioning benefits to hair.
May suitThose wanting added nourishment or antioxidant support in their haircare routine.
Worth knowingTocopherol is commonly included to help protect oils in a formula from oxidising and to offer light conditioning benefits. It is widely used in both skincare and haircare products.
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Acetic Acid pH adjusterspH adjuster
Helps regulate a product’s acidity for optimal hair and scalp performance.
May suitPeople using products that rely on precise pH levels for smoothness or shine.
Worth knowingAcetic acid is a simple organic acid also found in vinegar and is commonly used to keep formulas stable and effective. At low levels, it can help support cuticle lay-down, contributing to smoother-feeling hair.
Questions and Answers
Reviews: K18 Leave-In Molecular Repair Hair Mask
Written by Natarsha On 03/04/2026
4 people found this helpful