K18 Leave-In Molecular Repair Hair Mask Review | SkinSourcer
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The Shelf · Hair · Surface Tension: Treatments That Work Inside the Hair, and the Ones That Only Coat It

K18 Leave-In Molecular Repair Hair Mask
No. 01 in Edit 031

K18 Leave-In Molecular Repair Hair Mask

Treatments USA Approx. $75

The peptide is the whole product and it is the only one of its kind at this price. Four minutes on damp hair, no rinse, and you are done.

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Why we like the Leave-In Molecular Repair Hair Mask

  • The shortest treatment step in this edit
  • Genuinely changes how damaged hair handles
  • Fifty milliliters goes further than it looks
  • Scented, with geraniol, hexyl cinnamal and linalool declared
Texture
Light cream that disappears into damp hair
Key ingredients
sh-Oligopeptide-78 · Cetearyl Alcohol · Propylene Glycol · Behentrimonium Chloride
Fragrance
Scented. Parfum plus declared geraniol, hexyl cinnamal and linalool.
Best for
Bleached or chemically treated hair · Hair that has stopped holding a style
Works on
Breakage · Elasticity loss · Chemical damage
Made in
USA
Where to buy
Amazon
Price
$75, approximate
Listing checked
2026-08-13

Our verdict on the K18 Leave-In Molecular Repair Hair Mask

Worth it on damaged hair. Pointless on hair that is not damaged.

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Where the Leave-In Molecular Repair Hair Mask sits on The Shelf

Surface Tension: Treatments That Work Inside the Hair, and the Ones That Only Coat It Edit 031 · SURFACE TENSION Surface Tension: Treatments That Work Inside the Hair, and the Ones That Only Coat It Which treatments work inside the hair, which only smooth the outside, and why the difference is worth knowing before you spend seventy five dollars.

The rest of Surface Tension: Treatments That Work Inside the Hair, and the Ones That Only Coat It

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Reviewed 2026-08-12. K18 Leave-In Molecular Repair Hair Mask appears in Surface Tension: Treatments That Work Inside the Hair, and the Ones That Only Coat It. Every product on The Shelf is listed in the product index.