KÉRASTASE Resistance Serum Therapiste repairing leave-in hair serum — very damaged hair, heat protection to 450°F

This lightweight, leave-in serum targets fragile, over-processed strands to restore resilience and surface smoothness. Formulated to reinforce weakened fiber, it delivers nourishing actives that improve elasticity and replace lost moisture while adding thermal protection for everyday styling. Use on towel-dried hair before blow-drying or as a finishing touch to tame flyaways and disguise split ends.

How does this serum repair very damaged hair?

The formula supplies building blocks to help reconstruct the hair fiber and reduce the appearance of damage. Peptide and protein derivatives work together to strengthen weakened areas while hydrating agents restore softness and manageability.

• Gluco peptide supports fiber reinforcement and resilience.
• Wheat protein derivative improves flexibility and elasticity.
• Native plant cells deliver lasting hydration for softer feel.
• Lightweight emollients smooth rough cuticles for improved shine.

Will this serum protect my hair from styling heat?

Yes — the serum offers thermal protection up to 450°F when applied before heat styling. It forms a protective layer that helps reduce heat-driven dehydration and further weakening during blow-drying, flat ironing, or hot tools.

• Use 1–2 pumps on damp mid-lengths and ends prior to blow-drying.
• Creates a heat-resistant barrier during high-temperature styling.
• Helps maintain pliability so hair is less prone to breakage from heat.
• Can be reapplied sparingly to dry lengths as a finishing shield.

How do I incorporate it into my hair routine?

Apply a small amount to towel-dried hair focusing on weakened mid-lengths and ends, then blow-dry or style as usual. It’s compatible with conditioners and masks from the Resistance range for a comprehensive repair protocol.

• Apply 1–2 pumps from mid-lengths to ends on damp hair; leave in.
• Pair with Resistance Extentioniste Conditioner and Therapiste Mask.
• Use on dry hair for flyaways or to conceal split ends as needed.
• Suitable for use before hot tools thanks to heat protection properties.

Who is this for: KÉRASTASE Resistance Serum Therapiste is formulated for people with very damaged, weakened or over-processed hair who want to rebuild fiber strength, restore softness and protect lengths during heat styling. It suits those who regularly use hot tools, color or chemical treatments and need a leave-in treatment that combines repair, hydration and high-temperature protection without weighing hair down.

Ingredients

Cyclopentasiloxane, Dimethiconol, Dimethicone, Cetearyl Alcohol, Phenyl Trimethicone, Amodimethicone, Phenoxyethanol, Polyquaternium-37, Trideceth-5, Propylene Glycol Dicaprylate/Dicaprate, Steareth-20, Cetyl Hydroxyethylcellulose, Linalool, Glycerin, 2-Oleamido-1,3-Octadecanediol, Citronellol, Trideceth-10, Ppg-1 Trideceth-6, Geraniol, Glycine, Arginine, Proline, Tyrosine, Glutamic Acid, Chlorhexidine Digluconate, Serine, Benzyl Alcohol, Hydroxypropyltrimonium Hydrolyzed Wheat Protein, Isoeugenol, Safflower Glucoside, Alpha-Isomethyl Ionone, Trehalose, Tamarindus Indica Seed Polysaccharide, Myrothamnus Flabellifolia Leaf Extract, Fragrance.