K18 HeatBounce™ Conditioning Heat Protectant 118ml

Protect hair from the deep damage caused by blow-drying, straightening and curling with K18 HeatBounce™ Conditioning Heat Protectant 118ml, a lightweight leave-in treatment that provides heat protection from the cuticle to the cortex up to 232°C / 450°F.

Powered by K18's resilicore™ heat-shielding technology, HeatBounce™ is designed differently from traditional heat protectants that primarily coat the outside of the hair. Its technology penetrates deeper into the hair fiber, forming a protective shield where heat damage can occur while helping protect against breakage, dryness, dullness and color fade.

The lightweight conditioning formula also softens and detangles even damaged hair, making it ideal before blow-drying or hot-tool styling without leaving hair feeling heavily coated. In K18's testing, HeatBounce™ delivered 85% less breakage after blow-drying.

Protect → Condition → Detangle → Reduce Breakage → Preserve Color

Why You'll Love It

• Heat protection up to 232°C / 450°F
• Protects from the cuticle to the cortex
• 85% less breakage after blow-drying
• Helps prevent heat-related breakage
• Helps protect against color fade and maintain vibrancy
• Helps prevent the dry, dull feeling caused by repeated heat
• Powered by resilicore™ heat-shielding technology
• Lightweight conditioning formula
• Softens and detangles damaged hair
• Works before blow-drying, straightening and curling
• Can be applied to both damp and dry hair
• Suitable for all hair types and textures
• Suitable for hair extensions

What Does K18 HeatBounce™ Do?

Repeated heat styling doesn't only affect the outside of the hair.

High temperatures can cause damage deeper within the hair fiber, contributing to breakage, dryness, dullness and loss of color vibrancy.

HeatBounce™ uses K18's resilicore™ technology, inspired by resilin — a naturally occurring protein known for its resilience. K18 designed the technology's molecular size and composition to penetrate deeper into the hair fiber and form a protective shield within the cortex, rather than relying solely on surface protection.

K18's clinical testing found protection from the cuticle to the cortex at temperatures up to 232°C / 450°F, along with reduced breakage and improved protein stability under its test conditions.

Who Is It For?

Ideal for:

• Heat-damaged hair
• Bleached and highlighted hair
• Color-treated hair
• Dry or fragile hair
• Hair prone to breakage
• Hair that feels dry after blow-drying
• Regular straightener users
• Curling-iron users
• Frequent blow-drying
• Fine hair needing lightweight heat protection
• Thick, curly or coily hair
• Hair extensions
• Anyone regularly styling with heat

Pair Me With

• K18 Leave-In Molecular Repair Hair Mask – intensive 4-minute molecular repair treatment for hair damaged by bleach, color, chemical services and heat.
• K18 DAMAGE SHIELD Protective Conditioner – lightweight conditioning and everyday damage protection before styling.
• K18 Molecular Repair Hair Oil – finishing treatment for additional damage repair, smoothing, frizz control and surface heat protection.

What's the Best Heat Protectant for Damaged or Bleached Hair?

For already damaged or bleached hair, heat protection should do more than simply make the hair feel smoother before styling.

HeatBounce™ is specifically designed to protect from the outer cuticle into the cortex, where heat-related damage can occur. K18 reports 85% less breakage after blow-drying, making it particularly relevant for fragile hair that still needs regular heat styling.

It also conditions and detangles, so damaged hair gets:

Heat Protection + Less Breakage + Conditioning + Detangling + Color Protection

Can I Use K18 HeatBounce™ Before Straightening and Curling?

Yes.

Apply HeatBounce™ to towel-dried hair before blow-drying and to dry hair before using hot tools such as straighteners or curling irons.

You don't need to wait after application. K18 confirms that you can begin blow-drying or use your hot tools immediately after applying HeatBounce™.

The product also doesn't need heat to become protective — K18 states that the technology does not require heat activation.

K18 HeatBounce™ or Molecular Repair Hair Oil – Which Should I Use for Heat Protection?

Both offer heat-protection benefits, but they have different primary roles.

HeatBounce™ → deeper dedicated heat protection from cuticle to cortex + conditioning + detangling

Molecular Repair Hair Oil → damage repair + smoothing + frizz control + traditional surface heat protection

K18 specifically positions HeatBounce™ as the more comprehensive dedicated heat protectant because its technology is designed to protect as deep as the cortex.

For maximum protection, they can be used together: HeatBounce™ before heat styling and Molecular Repair Hair Oil as the finishing step.

HeatBounce conditioning heat protectant | K18 Hair

Before Blow-Drying

Apply throughout sectioned, towel-dried hair.

Brush or comb through to distribute evenly.

Start with a small amount and build only as needed.

Hair should feel soft and detangled, not coated.

Blow-dry and style as usual.

Before Straightening or Curling

Apply HeatBounce™ to dry hair before using hot tools.

Distribute evenly through the sections you intend to style.

You can begin using your hot tool immediately after application.

Water (Aqua) (Eau), Cellulose Gum, Isopentyldiol, Propanediol, Cetearyl Alcohol, Isopropyl Palmitate, Sodium Benzoate, C13-15 Alkane, sh-Oligopeptide-78 s-Fruit Fly Oligopeptide-1, (sh-Oligopeptide-78 s-Fruit Fly Oligopeptide-1) Peptides, Laurdimonium Hydroxypropyl Hydrolyzed Barley Protein, Helianthus Annuus (Sunflower) Seed Oil, Oryza Sativa (Rice) Bran Extract, Helianthus Annuus (Sunflower) Extract, Rosmarinus Officinalis (Rosemary) Leaf Extract, Tocopherol, Behentrimonium Chloride, Brassicatrimonium Chloride, Gluconolactone, Arginine, Coco-Glucoside, Lactic Acid, Cellulose, C12-20 Alkyl Glucoside, Citric Acid, Potassium Sorbate, Benzyl Alcohol, Isopropyl Alcohol, C14-22 Alcohols, Fragrance (Parfum), Amyl Salicylate, Benzyl Salicylate, Citronellol, Citrus Aurantium Peel Oil, Dimethyl Phenethyl Acetate, Geraniol, Geranyl Acetate, Isoeugenyl Acetate, Limonene, Linalool, Linalyl Acetate, Pinene, Tetramethyl Acetyloctahydronaphthalenes, Vanillin.

Always use the ingredient list printed on the current EU/Cyprus packaging as the final reference because formulations can be updated.