Keratin Sleek Diamond Sleek Smoothing Spray

4.8415
4.8415 out of 5 stars based on reviews
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Dull-looking hair with frizz? No problem! Our Diamond Sleek Shine-Coat Smoothing Spray, with its 8% Keratin Smoothing Complex and Argan Oil, shields and smooths hair to reduce frizz even in high humidity. It works by coating the hair fibre to boost light reflection from all angles, delivering a stunning diamond-like shine that lasts for up to 100 hours*. The lightweight, non-greasy, and non-sticky texture ensures a natural feel without any weigh-down. This heat-activated formula also provides essential protection from heat styling tools, including from blow drying and straightening, up to 230°C*. For best results, use as a final step after the 3-step Keratin Sleek System. After the Shampoo, Conditioner, or Mask, apply Diamond Sleek Spray to achieve a long-lasting sleek look with incredible, polished shine. Vegan Formula**. Approved by Cruelty-Free International.

*Instrumental tests using standard shampoo + Diamond Sleek Spray
**No animal-derived ingredients or by-products

Dull-looking hair with frizz? No problem! Our Diamond Sleek Shine-Coat Smoothing Spray, with its 8% Keratin Smoothing Complex and Argan Oil, shields and smooths hair to reduce frizz even in high humidity. It works by coating the hair fibre to boost light reflection from all angles, delivering a stunning diamond-like shine that lasts for up to 100 hours*. The lightweight, non-greasy, and non-sticky texture ensures a natural feel without any weigh-down. This heat-activated formula also provides essential protection from heat styling tools, including from blow drying and straightening, up to 230°C*. For best results, use as the final step in the Garnier 3-Step Keratin Sleek System. After the Shampoo, Conditioner, or Mask, apply Diamond Sleek Spray to achieve a long-lasting sleek look with incredible, polished shine. Vegan Formula**. Approved by Cruelty-Free International.

*Instrumental tests using standard shampoo + Diamond Sleek Spray
**No animal-derived ingredients or by-products

Up to 100H Diamond-Like Shine: Coats the hair fibre to boost light reflection from all angles, providing your hair with a spectacular, polished shine that lasts for up to 100 hours*.

Up to 72H Frizz-Free Sleek: Our formula shields and smooths hair to reduce frizz even in high humidity, delivering a sleek, polished look that lasts for up to 72 hours*.

Heat Activated Formuila: This formula requires blow-dryer heat to activate its smoothing power and provides thermal protection from styling tools up to 230°C*, keeping your hair healthy.

Keratin & Argan Oil: Powered by an 8% Keratin Smoothing Complex and Argan Oil, this spray actively smooths the hair fibre for a sleek, and shiny result.

Lightweight & Non-Greasy: Enjoy a super sleek finish without the heavy feel. The texture is lightweight, non-greasy, and non-sticky, ensuring your hair has a natural, bouncy feel.

After using the Keratin Sleek routine, towel dry and spray the product liberally on damp hair. Blow-dry hair by sections with a brush, putting tension on the hair. Heat is required to activate the formula.

Key Ingredient

Garnier Color Match logo

Argan

Used for centuries in skincare and haircare, argan oil is an extremely rich golden liquid which is quickly absorbed. This transformative ingredient unleashes nourishment, fatty acids, and vitamin E, soothing and deeply hydrating the skin, and restoring shine to dull hair.

Know more

AQUA / WATER • GLYCERIN • DIPROPYLENE GLYCOL • PEG-60 HYDROGENATED CASTOR OIL • LAURETH-4 • ARGANIA SPINOSA KERNEL OIL • STEARAMIDOPROPYL DIMETHYLAMINE • SODIUM HYDROXIDE • ISONONYL ISONONANOATE • HYDROLYZED CORN PROTEIN • HYDROLYZED SOY PROTEIN • HYDROLYZED WHEAT PROTEIN • CAPRYLYL GLYCOL • LACTIC ACID • POLYSILICONE-29 • HEXYL LAURATE • PHENOXYETHANOL • PARFUM / FRAGRANCE

*Please be aware that ingredient lists for products in our brand are updated regularly. Please refer to the ingredient list on the product package for the most up-to-date list of ingredients to ensure it is suitable for your personal use.

FAQs

What does the Garnier Diamond Sleek Shine-Coat Smoothing Spray do?

Garnier Diamond Sleek Shine-Coat Smoothing Spray is a leave-in smoothing spray designed for dull-looking hair prone to frizz. Powered by an 8% Keratin Smoothing Complex and enriched with Argan Oil, it works by coating the hair fibre to boost light reflection from all angles — delivering a polished, diamond-like shine. It also helps smooth and shield hair to reduce the appearance of frizz, even in humid conditions, while providing heat protection up to 230°C.

*Instrumental tests. Results observed after use of standard shampoo + Diamond Sleek Spray.

How long does the diamond-like shine last?

Garnier Diamond Sleek Spray is instrumentally tested to deliver shine that lasts for up to 100 hours — that's over four days of polished, light-reflecting results. The formula works by coating the hair fibre's surface to enhance light reflection from all angles, giving hair a sleek, luminous finish that visibly persists beyond a single wash day.

Does Garnier Diamond Sleek Spray control frizz in humidity?

Yes. Garnier Diamond Sleek Spray is formulated to help reduce the appearance of frizz, even in humid conditions, with results that last for up to 72 hours in instrumental testing. The formula shields and smooths the hair fibre's surface, helping to maintain a sleek, polished look through environmental moisture exposure.

*Instrumental tests. Results observed after use of standard shampoo + Diamond Sleek Spray. Test conducted under high-humidity conditions.

What is the Keratin Smoothing Complex in Diamond Sleek Spray?

The 8% Keratin Smoothing Complex is the core active blend in this formula. Keratin is the primary structural protein that makes up the hair fibre — when hair is damaged by heat, colour or mechanical stress, the cuticle becomes rough and uneven. The Keratin Smoothing Complex helps coat and smooth the hair surface, improving the way hair reflects light and reducing the friction that causes frizz.

The formula is also enriched with Argan Oil, known for its conditioning and shine-enhancing properties, contributing to the overall smooth and luminous finish.

How do you use Garnier Diamond Sleek Spray and does the order matter?

This spray is a heat-activated leave-in formula, meaning it requires blow-dryer heat or a straightening iron to activate its full smoothing power. Here's how to use it: 1. Wash hair with your shampoo of choice (ideally the Garnier Keratin Sleek Shampoo for best results), 2. Follow with conditioner or mask if needed, 3. Apply Diamond Sleek Spray to damp hair before drying, 4. Blow-dry to activate the formula and unlock the smoothing and shine benefits, 5. Style as usual — the formula also protects hair from heat tools up to 230°C. For optimal results, use as the final step in the Garnier 3-Step Keratin Sleek System. *Instrumental tests. Results observed after use of standard shampoo + Diamond Sleek Spray.

Is Garnier Diamond Sleek Spray vegan and cruelty-free?

Yes on both counts: Vegan Formula — the Diamond Sleek Spray contains no animal-derived ingredients or by-products. Approved by Cruelty-Free International — the product carries the official Leaping Bunny certification, one of the most recognised cruelty-free standards globally

Reviews

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Overall Rating

4.8
343 out of 348 (99%) reviewers recommend this product

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    Filter Reviews

    1 to 8 of 367 Reviews
    1 – 8 of 367 Reviews
    Review1
    Votes0

    Loveeeee

    6 days ago
    My hair has never looked so shiny and it is so much less frizzy!

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Leaves hair so silky

    9 days ago
    My hair looks absolutely silky and fabulous because of this product. Can’t get enough of it! It’s so good

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Not worth the hype at all

    13 days ago
    It leaves my hair sticky and feeling dry, worse than usual heat products

    No, I do not recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Shiny hair!

    28 days ago
    I received this about a month ago and wanted to use it a few times before reviewing it. The shine it gives is amazing, and makes my hair look less frizzy.

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Would recommend x1000

    a month ago
    I had received this product just a few weeks ago and WOW this change the game for me. Having extensions my natural hair can frizz up sometimes and you can really see the difference between my hair and extensions but this eliminated that completely and made my hair soooo soft and the shine was amazing. A little does go a long way with this and my mums stolen it from me now! 🤣🤞🏻

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Glass hair in a bottle!

    a month ago
    Already purchased a second bottle of this! I just can’t get enough!! Smells delicious and also leaves my hair feeling super soft yet still light and bouncy! Now a firm favourite in my fair care routine!

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Love it

    a month ago
    I was given the opportunity to try this product in exchange from my honest opinion I noticed it leaves my hair super shiny and smooth Super simple to use and you don’t have to use a lot My hair feels light and it doesn’t become oily

    Yes, I recommend this product.

    Originally posted on boots.com

    Review1
    Votes0

    Shine

    a month ago
    ✨ Shine bright like a diamond with every strand. #DiamondSleek

    Yes, I recommend this product.

    Originally posted on boots.com

    1 – 8 of 367 Reviews
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