KÉRASTASE Resistance Heat Protection Serum Ciment Thermique 5.1 oz — Thermal Protection to 450°F, Strengthens & Reduces Breakage

KÉRASTASE Resistance Heat Protection Serum (Ciment Thermique) is a leave-in blow-dry primer that shields hair from heat up to 450°F while strengthening fibers and reducing breakage.

This lightweight, fortifying serum from KÉRASTASE’s Resistance line is formulated to repair and protect damaged, brittle hair during heat styling. Infused with nourishing resurrection plant sap and strengthening ingredients, the product seals moisture into lengths and ends, smooths the cuticle, and helps control flyaways. Apply to towel-dried hair before blow-drying to create a resilient base for styling tools and to visibly boost shine.

How does this serum protect hair from heat styling?

The primer forms a protective coating that helps shield hair strands from temperatures up to 450°F, reducing the mechanical stress heat can cause. Rather than adding heavy weight, it leaves a fine barrier that helps heat glide across the fiber for smoother styling results.

• Thermo-protection rated up to 450°F for styling tools
• Lightweight formula that won’t weigh down fine hair
• Promotes smoother airflow during blow-drying for faster styling

Can it repair and reduce breakage on damaged hair?

While not a clinical repair treatment, the serum helps rebuild resilience by improving elasticity and locking in moisture at the lengths and ends. Regular use as part of the Resistance system supports stronger hair that resists snapping during brushing and styling.

• Contains ingredients that encourage moisture retention and flexibility
• Seals cuticles to reduce friction-related breakage
• Pairs with Resistance conditioner and mask for cumulative strengthening

What’s the best way to use Ciment Thermique for daily styling?

Use a quarter-size amount on clean, towel-dried hair, focusing on mid-lengths and ends; do not rinse. Finish by blow-drying, then style with heated tools as desired. It layers well under other KÉRASTASE products if you use a full routine.

• Apply to towel-dried hair; distribute with fingers or a comb
• Blow-dry immediately; then use flat or curling irons if needed
• Use after shampoo and conditioner for best results

Will this weight down fine hair or leave residue?

The serum is designed to be lightweight and non-greasy so it protects without heavy buildup when used in recommended amounts. For very fine or oily hair, apply sparingly to lengths and ends and avoid the roots to maintain natural volume.

• Non-greasy finish when applied correctly
• Use sparingly on fine hair to preserve lift at the roots
• Comb through to ensure even distribution and avoid hotspots

Who is this for: KÉRASTASE Resistance Heat Protection Serum is ideal for anyone who frequently uses heat styling and wants to strengthen hair that is weakened, brittle, or showing signs of breakage. It suits all hair types but is particularly beneficial for strands needing elasticity and moisture retention—pair it with Resistance Extentioniste Conditioner and Resistance Therapiste Hair Mask for a full-strengthening regimen.

Ingredients

Water, Cyclopentasiloxane, Propylene Glycol, Dimethiconol, Triethanolamine, Phenoxyethanol, Peg/Ppg-17/18 Dimethicone, Carbomer, Behentrimonium Chloride, Polyquaternium-4, Potato Starch Modified, Hydroxypropyl Guar, Methylparaben, Limonene, Amodimethicone, Cetyl Alcohol, Quaternium-87, Behentrimonium Methosulfate, Quaternium-33, Trideceth-6, 2-Oleamido-1,3-Octadecanediol, Geraniol, Linalool, Glycerin, Citronellol, Citral, Cetrimonium Chloride, Trehalose, Tamarindus Indica Seed Polysaccharide, Myrothamnus Flabellifolia Leaf Extract, Fragrance.