The Review
Kerastase Ciment Thermique Review
A full review of the Kerastase Resistance Ciment Thermique blow dry primer: the strengthening milk for damaged hair, its printed 450 degree figure, the damp hair protocol, and who should choose the Genesis fluid instead.

How this review was made: from the manufacturer's published formula and specifications, the live Amazon listing, and recurring themes in owner commentary. Eclat Press does not claim hands-on testing it has not done, and publishes no scores.
A milk built for the Resistance brief
The Resistance line exists for hair damaged by chemical services and repeated styling, and Ciment Thermique is its heat step. The listing names a Pro-Keratine Complex and Vita-Topseal as the formula's working pair, framed by the brand as resurfacing and strengthening care that heat itself helps to seal onto the hair. Read cosmetically, what that means in the hand is a rich but not greasy milk that makes rough lengths feel smoother and more coherent before the dryer starts, so the brush passes with less snagging and the finished hair looks more polished. It is not a moisture mask in a tube and it is not a finishing serum; it is a protective blow dry primer with a strengthening story, and judged on that job it is complete.
The printed figure and what it does not promise
The US listing for this product states protection against heat up to 450 degrees F, and this review repeats that figure exactly as the brand prints it, for this product. What the figure describes is the protective film's published working range, not a guarantee about any individual head of hair, and the brand does not present the milk as making styling damage free. Owners who treat the number as permission to run an iron at its maximum daily are misreading both the product and this page. Used as directed, on damp hair, at sensible tool temperatures, the ownership picture below is what the product actually delivers.
Application is a damp hair ritual
Washed, towel dried hair, a chestnut sized amount warmed between the palms, massaged through lengths and ends, then the blow dry. Each step earns its place: towel drying stops the milk being diluted, palm warming spreads a thick cream evenly, and lengths and ends placement keeps the richer formula off the roots. The most common disappointment in owner commentary traces to using it as a dry hair iron primer, a job it was never directed for, where it coats and steams. Fine hair owners should start at half the directed dose; the formula is concentrated and the full amount is calibrated for damaged hair with more thirst.
What owners report over a full tube
Praise repeats around blow drying becoming quicker and smoother, hair feeling stronger in the hand with less breakage visible around the front, and a shine that reads as healthy rather than coated. Complaints repeat around the salon fragrance, around heaviness when fine hair meets a full dose, and around the luxury tier for a 150 ml tube that daily stylers finish steadily. The pattern is a product that satisfies exactly the audience printed on its tube, damaged hair, and merely tolerates everyone else.
Ciment Thermique is the protectant this category keeps circling back to, because it was built for the hardest brief in heat styling: hair already weakened or damaged, put under a dryer and brush on a regular rhythm.
From the verdict
In Owners' Hands
Recurring themes, in aggregate and without numbers we cannot stand behind.
What owners praise
- Hair feeling stronger and smoother after blow drying, with less visible breakage around the front lengths
- Faster, easier blow drying with a brush, the glide the brand promises showing up in practice
- Shine and softness on hair that had turned rough from repeated heat styling
What owners question
- Fine hair owners reporting heaviness when the full directed amount is used
- The scent, a deliberate salon fragrance, being more present than some buyers expect
- Owners who apply it to dry hair before flat ironing reporting a coated feel, against the damp hair directions
Consider Instead

Kérastase Genesis Défense Thermique Blow Dry Primer
The lighter Kerastase route, a Genesis fluid spray for weakened, breakage prone hair that a cream would weigh down.

Redken Quick Blowout Heat Protectant Spray
The faster, lighter blow dry primer spray, with its 450 degree figure printed on the bottle, when drying time matters more than strengthening care.
Questions, Answered
Can Ciment Thermique be used before a flat iron on dry hair?
It is directed for damp hair before blow drying. On a day when hair is already dry and an iron is the only tool, a dry safe product such as the Moroccanoil Perfect Defense aerosol in this edit is the correct format. If the iron follows the blow dry in the same session, the milk applied before drying is already in the hair doing its job.
How is Ciment Thermique different from Defense Thermique?
Different lines, different problems. Ciment Thermique is Resistance, a strengthening milk for damaged hair. Defense Thermique is Genesis, a light fluid for weakened hair prone to falling through breakage. The comparison is covered in the micro guides here, and hair that is both damaged and fine usually starts with the Genesis fluid and graduates only if it needs more.
Keep Researching
Every page in the Heat Protectants edit.
- 01Heat Protectants: the hubHub
- 02Best Heat Protectants 2027Best of
- 03Spray vs Cream vs Serum Heat ProtectantsGuide
- 04How to Apply Heat Protectant ProperlyGuide
- 05Heat Protectant for Fine HairGuide
- 06Color Wow Dream Coat Supernatural Spray ReviewReview
- 07OUAI Leave In Conditioner ReviewReview
- 08Kerastase Ciment Thermique vs Redken Quick BlowoutComparison
- 09Olaplex No.9 Serum vs OUAI Leave In ConditionerComparison
- 10Heat Protectants Buying GuideBuying guide
- 11Heat Protectant Care and Keeping: Fixing Steaming, Stickiness and Styles That Will Not HoldCare
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