KÉRASTASE Resistance Extentioniste Thermique Heat Protecting Leave-In Cream, 450°F Protection & Strengthening

KÉRASTASE Resistance Extentioniste Thermique is a leave-in blow-dry primer that shields hair from high heat, helps seal split ends, and reinforces mid-lengths and ends for healthier-looking lengths.

Designed for weakened hair that needs stronger, longer lengths, this lightweight cream is applied to wet hair before blow-drying to protect against thermal stress and mechanical damage. The formula combines Creatine R with ceramides and taurine to support the fiber’s internal structure, promote elasticity, and retain moisture — all while delivering heat protection up to 450°F.

How does this product protect hair during blow-drying?

Extentioniste Thermique acts as a thermal shield and a slip-enhancing primer so hot styling tools glide more smoothly, reducing friction and breakage. The heat protection component is formulated to withstand high temperatures while preserving the hair’s surface.

• Protects up to 450°F to guard against thermal stress
• Reduces friction during styling for less mechanical damage
• Applied to mid-lengths and ends to target vulnerable areas

What strengthening ingredients are included and what do they do?

The cream features Creatine R, a proprietary complex built around creatine to reinforce the hair’s internal structure and support longer, stronger lengths. Ceramides and taurine complement the formula by improving surface resilience, moisture retention, and elasticity.

• Creatine R helps rebuild and fortify the fiber core
• Ceramides smooth the cuticle and enhance shine
• Taurine supports elasticity and overall hair health

How should I use Extentioniste Thermique for best results?

Work a quarter-sized amount into towel-dried hair, concentrating on mid-lengths and ends rather than the roots. Follow by blow-drying and styling as usual; pairing with the Extentioniste Shampoo and Conditioner increases the regimen’s strengthening benefits.

• Apply to damp hair before heat styling
• Use sparingly near roots to avoid weighing hair down
• Combine with matching Extentioniste products for optimal results

Will it help with split ends and breakage?

The formula is designed to seal and smooth split ends temporarily while reinforcing weakened strands to reduce the risk of further breakage. In brand testing, use as a blow-dry primer contributed to significantly less breakage during styling.

• Seals and smooths the appearance of split ends
• Strengthening actives lower breakage during heat styling
• Best used regularly as part of a strengthening routine

Who is this for: KÉRASTASE Resistance Extentioniste Thermique suits anyone with weakened, breaking, or length-retaining hair who styles with heat and wants a lightweight barrier that strengthens and protects mid-lengths and ends. It’s ideal for those building a targeted haircare routine to support length, shine, and improved elasticity without heavy residue.

Ingredients

Water, Isopropyl Myristate, Dimethicone, Triethanolamine, Amodimethicone, Phenoxyethanol, Carbomer, Polyquaternium-4, Potato Starch Modified, Hydroxypropyl Guar, Behentrimonium Chloride, Trideceth-6, Amyl Cinnamal, Hexyl Cinnamal, Isopropyl Alcohol, Benzyl Alcohol, Linalool, Hydroxycitronellal, Cetrimonium Chloride, Citronellol, Limonene, Benzyl Cinnamate, Creatine, 2-Oleamido-1,3-Octadecanediol, Taurine, Parfum, Fragrance.