K18 HeatBounce conditioning heat protectant bottle on a pink background

K18 leave-in conditioner bottle with promotional text on a colorful background

HeatBounce conditioning heat protectant 4oz

Before and after comparison of a woman's hair with K18 HeatBounce product.

Before and after comparison of a woman with hair treated using K18 products.

Person with long hair using a pink comb against a pink background with text about hair care.

Promotional graphic for HeatBounce heat protectants with a scientific diagram of hair follicle and text about heat protection.

K18 HeatBounce heat protectant and oil on a colorful background with text highlighting features.

Woman with styled hair holding a bottle of K-8 hair product, with text about heat protection and breakage reduction.

K18 Heatbounce Heat protectant with ressilicore heat-shielding technology on a pink background

K18 heat bounce and hair mask products on a pink background with text about damage repair and protection.

Four women using a hair styling tool with text indicating different styles you can do with heatbounce.

Three women with styled hair against a colorful background with text about hair care.

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4.8

Rated 4.8 out of 5 stars

511 Reviews

HeatBounce conditioning heat protectant

Name: HeatBounce conditioning heat protectant 4oz
Brand: K18Hair
SKU: K18-35092
Price: 48.00 USD
Availability: InStock
Rating: 4.8 (511 reviews)

The future of heat protection

HeatBounce conditioning heat protectant 4oz $48.00

Description

This leave-in conditioning heat protectant detangles, softens, and delivers deeper heat protection than ever before*—for 85% less breakage after blow drying⁷.

How to use

Apply throughout sectioned hair, brushing through to help with even distribution. Less is more. Start small and build as needed. Hair should feel soft and tangle-free, but not coated.

Use on towel-dried hair before blow drying and on dry hair before hot tools

More to know

resilicore™ heat-shielding technology is inspired by proteins in nature that can withstand extreme temperatures. Unlike traditional heat protectants that only coat the cuticle, the size + molecular makeup of resilicore™ allows it to penetrate deeper than ever before*, into hair's inner cortex where heat damage can occur, forming a protective shield that fortifies from within.

Conditioning blend conditions, softens, and detangles even damaged hair

Created for all hair types + textures. Can be used on extensions.

Key benefits

Protects from heat up to 450°F

85% less breakage after blow drying⁷

Lightweight formula conditions, softens, and detangles even damaged hair

*Heat protection observed on hair in clinical testing after application of HeatBounce and use of 450℉ (232℃) flat iron on dry hair.

¹Results observed as a reduction in hair breakage in scientific testing after application of HeatBounce and use of 450℉ (232℃) flat iron on dry hair.

²Results observed as an increase in protein stability in scientific testing after application of HeatBounce on damp hair and exposure to 450℉ (232℃) flat iron on dry hair.

³Results observed as a reduction in color change in scientific testing after application of HeatBounce on dry hair and use of 450℉ (232℃) flat iron.

⁴Results observed as a reduction in hair breakage in scientific testing after application of HeatBounce on dry hair and use of 450℉ (232℃) flat iron.

⁵Results observed as a reduction in hair breakage in scientific testing after application of HeatBounce on dry hair and use of 450℉ (232℃) flat iron.

⁶Results observed as an increase in protein stability in scientific testing after repeated exposure to UV and HeatBounce application.

⁷Reduction in hair breakage observed in clinical testing after application of high heat blow dry on wet hair.

Ingredients

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 Annus (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.

pairs well with

full-size leave-in molecular repair hair mask

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Rated 4.7 out of 5 stars

5,545 Reviews

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AstroLift™ reparative volume spray

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Rated 4.6 out of 5 stars

414 Reviews

Interdimensional biotech reverses bounce-depleting damage for 2-day hold

Description

This leave-in conditioning heat protectant detangles, softens, and delivers deeper heat protection than ever before*—for 85% less breakage after blow drying⁷.

got questions?

Get started here

Is HeatBounce activated by heat?

No, HeatBounce does not need to be activated to protect from heat.

Do I have to wait to use heat after applying HeatBounce?

No, you can blow dry or use hot tools immediately after applying HeatBounce.

How is HeatBounce different from traditional heat protectants?

HeatBounce is powered by resilicore™ heat-shielding technology, an innovation inspired by resilin—a natural protein that can withstand extreme temperatures. Unlike traditional heat protectants that only coat the outside cuticle layer of hair, the size + molecular makeup of resilicore™ allows it to penetrate deeper than ever before*, into the cortex where heat damage can occur, forming a protective shield that fortifies from within.

*Heat protection observed on hair in clinical testing after application of HeatBounce and use of 450℉ (232℃) flat iron on dry hair

What’s the difference between molecular repair hair oil and HeatBounce?

While the molecular repair hair oil and HeatBounce have heat protection benefits, HeatBounce defends against heat from the cuticle¹ to the cortex², going as deep as heat damage goes to help protect against color fade, dry feeling, dullness, and breakage. The oil delivers traditional heat protection on the outer layers of hair and clinically proven damage repair.

¹Results observed as a reduction in hair breakage in scientific testing after application of HeatBounce and use of 450℉ (232℃) flat iron on dry hair
²Results observed as an increase in protein stability in scientific testing after application of HeatBounce on damp hair and exposure to 450℉ (232℃) flat iron on dry hair.

When do I use HeatBounce in my routine?

After shampooing, apply the K18 mask (wait 4 minutes) or DAMAGE SHIELD conditioner. Then, apply HeatBounce and AstroLift™ before blow drying or air drying. Use HeatBounce again before any hot tools. Finish with K18 oil and use AirWash™ to refresh hair between washes.

How often can I reapply HeatBounce?

Apply HeatBounce every time before you apply heat, including if you switch between blow drying to hot tools.

the future of heat protection

less breakage after blow drying⁷

degree heat protection from cuticle¹ to cortex²

Inspired by proteins in nature that can withstand extreme temperatures.

EXPLORE THE SCIENCE

heat protect + condition in one step

how to use HeatBounce

1. Apply throughout sectioned hair, brushing through to help with even distribution.

2. Less is more. Start small and build as needed. Hair should feel soft and tangle-free, but not coated.

3. Use on towel-dried hair before blow drying and on dry hair before hot tools.

learn more on our blog

how to use HeatBounce conditioning heat protectant

Blow dry, curl + straighten your hair—without damage.

Meet HeatBounce: Deeper Heat Protection Than Ever Before*

What Hot Tools Are Really Doing to Your Hair

If your routine involves heat—this one's for you.

feel what's possible with K18

See how K18 unlocks our community's expression

4.8

Rated 4.8 out of 5 stars

Based on 511 reviews

97%would recommend these products

Reviews Summary

Customers say this heat protectant leaves hair silky and smooth while styling. Many reviews highlight its lightweight formula that doesn't weigh hair down. The spray effectively detangles and adds shine without feeling greasy. Users with fine, curly, and color-treated hair appreciate its versatility. Common feedback mentions the pleasant scent and easy application. While most find it perfect for daily use, some note that a light application works best, especially for fine hair.

Customers Talked About

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511 reviews

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Christy H.
Verified Buyer
Reviewing
HeatBounce conditioning heat protectant 4oz
I recommend this product
Age 35 - 44
Hair Concern Chemical damage, Heat damage, Color-care, Dryness, Fragile/brittle hair
Hair Type Fine/Thin
My Results Visible Difference, Stronger Hair, Smoother Hair, Shinier Hair, Cleaner, fresher hair
Rated 5 out of 5 stars
3 days ago
Great heat protectant
I use this now after every wash to protect before styling. Works wonders and I can tell it is protecting my hair because my hair strength is improving.
Was this helpful?
K
K18Hair
6 minutes ago
Thank you so much for this amazing review, Christy! We're absolutely thrilled to hear that you love the HeatBounce conditioning heat protectant and that you're using it after every wash! It's wonderful that you can feel it protecting your hair and that your hair strength is actually improving - that's exactly what we love to hear about our heat protection! We're so excited that you're experiencing such fantastic results and thanks for your incredible 5-star review! 💛
Deyanirys S.
Verified Buyer
Reviewing
HeatBounce conditioning heat protectant 4oz
I recommend this product
Age 45 - 54
Hair Concern Fragile/brittle hair, Color-care, Heat damage
Hair Type Fine/Thin, Grey Hair
My Results Stronger Hair, Less Breakage, Shinier Hair, Smoother Hair, Less Frizz
Rated 5 out of 5 stars
1 week ago
A miracle
Best product there is to dry your hair. Either by blow drying or curling iron. Simply the best.
Was this helpful?
K
K18Hair
1 week ago
Thank you so much for this incredible review, Deyanirys! 💛 We're absolutely thrilled to hear that you think the HeatBounce conditioning heat protectant is a miracle - that's such an amazing compliment! It's wonderful that it's working so beautifully for you whether you're blow drying or using a curling iron, and we love that you consider it simply the best! We're so excited that you're loving the product and thanks for your fantastic 5-star review!
Theresa H.
Verified Buyer
Reviewing
HeatBounce conditioning heat protectant 4oz
I recommend this product
Age 55 - 64
Hair Concern Chemical damage, Heat damage, Color-care, Frizz, Dryness
Hair Type Fine/Thin, Thick/Coarse, Straight/Wavy, Grey Hair
My Results Less Frizz, Bouncy Hair, Visible Difference, Stronger Hair, Soft Touchable Hair
Rated 5 out of 5 stars
1 month ago
LOVE HEATBOUNCE !!
I absolutely LOVE this product and use it everyday! A little goes a long way. It's a great way to refresh hair between shampoos. Prefer using HeatBounce over using the K18.. Compliments K18 Dry Shampoo
Was this helpful?
K
K18Hair
4 weeks ago
Thank you so much for your incredible review, Theresa! 💛 We're absolutely thrilled to hear that you LOVE HeatBounce and use it every day! It's amazing that you've discovered how a little goes a long way - that's one of the things that makes this product so special. We love that you're using it to refresh your hair between shampoos and that it's become your go-to over other products! It's also fantastic to hear how perfectly it compliments the K18 Dry Shampoo - what a dream team! ✨ Thanks for your wonderful 5-star review! 🙌
Jane G.
Verified Buyer
Reviewing
HeatBounce conditioning heat protectant 4oz
I recommend this product
Age 45 - 54
Hair Concern Split-Ends, Dryness
Hair Type Fine/Thin
My Results Visible Difference, Smoother Hair, Shinier Hair
Rated 5 out of 5 stars
1 month ago
HeatBounce conditioning heat protectant
Leaves my hair shiney , healthy and super straight with using the flat iron. Love this product!
Was this helpful?
K
K18Hair
1 month ago
Thank you so much for your fantastic review, Jane! 💖 We're absolutely thrilled to hear that HeatBounce is giving you such amazing results - shiny, healthy, and super straight hair sounds perfect! It's wonderful to know our conditioning heat protectant is delivering exactly what you're looking for with your flat iron routine. Your 5-star review means the world to us!
Jessica M.
Verified Buyer
Reviewing
HeatBounce conditioning heat protectant 4oz
I recommend this product
Age 35 - 44
Hair Concern Chemical damage, Heat damage, Color-care, Fragile/brittle hair, Split-Ends
Hair Type Fine/Thin
My Results Less Frizz, Less Breakage, Stronger Hair, Defined Curl/Wave Pattern, Soft Touchable Hair
Rated 5 out of 5 stars
1 month ago
That smell!!
Wow this stuff smells soooooookoo good wow!!!
Was this helpful?
K
K18Hair
1 month ago
Thank you so much for this amazing review, Jessica! We're absolutely thrilled to hear that you love the scent of our HeatBounce conditioning heat protectant! Your excitement about the fragrance truly makes our day and means the world to us - we're so grateful to have you as part of our K18 community! 💛

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HeatBounce conditioning heat protectant

Description

Description

how to use HeatBounce conditioning heat protectant

Meet HeatBounce: Deeper Heat Protection Than Ever Before*

What Hot Tools Are Really Doing to Your Hair