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Kerastase

Premiere Filler Fondamental Repairing Anti-Frizz Serum

Heat protectant / Serum, medium-weight

  • Heat protectant
  • serum
  • Sulfate-free
  • Cruelty-free · label states
Size3.04 fl oz (90 ml)
Price$51.21seen at one store · 3.04 oz

Add it to your products. We’ll tell you if it’s ever recalled.

Scent:

The ingredient list declares fragrance. What it smells of is not stated, and we do not guess.

Manufacturer page: valley-beauty.com

Personal fit

Is this right for you?

Complete the consultation to see how well this product fits your hair and your goals. With 6,000+ products in our library, we can match you to the right ones.

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  • Find products that do the same job at a lower cost.
  • Your goals, scalp, damage history, water, budget, and scent preferences all shape your plan.

$49 with 60 days of follow-up questions and plan updates

$99 with 12 months. Pay once; the year renews only if you choose.

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Not enough priced heat protectants to place it

We have not priced enough heat protectants to place this one.

Price and stores

Great for

A wide range of haira middle-of-the-range weight

Maybe skip if

this product has a scent
Curly-method routinesthese silicones need a detergent to remove
Very dry or damaged hairit contains fast-drying alcohol
Tight budgetsit sits in the upper price tiers

How much heat protection you need depends on how often and how hot you style. Your consultation takes that into account.

What the formula actually does

Read from the label, not the marketing

Each row says where it comes from: F means we derived it from this product’s own ingredient list, S means it is a claim the brand makes that the formula neither confirms nor contradicts.

Weight on the hair Medium

Middle of the range: noticeable on fine hair, light on coarse hair.

Slip and detangling Moderate

Conditioning agents are present, lower in the list.

Needs detergent to remove Yes

Water-insoluble silicones or waxes: a detergent wash is what removes them.

Water-binding (humectants) None found

No humectants, so nothing here pulls water into the hair.

Fast-drying alcohol Present

Contains fast-drying alcohol, which speeds drying but can leave hair feeling dry.

Fragrance Prominent

Fragrance is in the first eight ingredients, so it makes up a larger share of the formula.

from the formula stated by the brand reported by reviewers Scale: 1 dot low · 5 dots high, within this product type.

Ingredients that matter

The ingredients that change a decision

The workhorse ingredients, plus anything lower down that changes a decision. The chips name what an ingredient does. They are not safety scores, and no ingredient here is rated good or bad on its own.

IngredientWhat it doesWhy it mattersChip
WaterAqua solvent The base everything else is dissolved in Neutral
Isopropyl Myristate light ester Light slip without much weight Softens
Dimethicone silicone Spreads heat across the strand Buildup
Triethanolamine pH adjuster Fine-tunes the pH pH balancer
Amodimethicone silicone A little heat-spreading smoothing Buildup
FragranceParfum fragrance The scent Fragrance
Phenoxyethanol preservative Keeps the product from spoiling Stabilizes
Carbomer thickener Adjusts the texture Holds
Limonene fragrance The scent Fragrance
Hydrolyzed Vegetable Protein PG-Propyl Silanetriol film former A supporting film former Protein
Isopropyl Alcohol drying alcohol A small amount, for fast drying Drying
Linalool fragrance The scent Fragrance
What the list leaves out, and what it carriesNo sulfates. Contains fragrance. The silicones here need a detergent wash to come off. Fast-drying alcohol is in the list.
Full ingredient list (28)

In the US, ingredients above 1% are listed from most to least. Below 1% they can appear in any order. Each note keeps three things apart: what the ingredient generally does, its role in this type of product, and what its position can tell you.

  • 1 Water · Aqua
    General function

    The base of almost every rinse-off and cream hair product. It carries everything else and is normally the first ingredient on the label.

    Leading ingredient

    Listed in the first three ingredients, it is likely a structural part of this formula.

    • solvent
  • 2 Isopropyl Myristate
    General function

    A very light ester that makes products glide and disappear quickly on the hair.

    Leading ingredient

    Listed in the first three ingredients, it is likely a structural part of this formula.

    May suitFine or easily flattened hair

    A light emollient: it softens the surface with noticeably less weight than an oil or a butter.

    May suitFrizz-prone, damaged, or high-friction hair

    Spreads thin and lowers friction between strands without the heaviness of a fixed oil.

    PubChem
    • light ester
    • emollient
  • 3 Dimethicone
    General function

    The most common conditioning silicone. It coats the strand for shine, slip, and frizz control, and needs a detergent (not just water) to wash out.

    Leading ingredient

    Listed in the first three ingredients, it is likely a structural part of this formula.

    May suitClimate-sensitive or frizz-prone hair

    A surface film slows how quickly humidity reaches the cortex, which is what limits swelling-driven frizz in damp air.

    May suitFrizz-prone, damaged, or high-friction hair

    Lays a smooth film along the cuticle, which lowers combing friction and flattens the surface irregularities that read as frizz.

    May not suitBuild-up-sensitive routines

    Dimethicone does not disperse in water. On a routine that skips detergent it stays on the hair and accumulates wash after wash.

    • silicone
    • emollient
    • conditioning agent
  • ▾Below about here, the order stops meaning much. These are usually used at 1% or less.
  • 4 Triethanolamine
    General function

    A base used in trace amounts to neutralise acidic polymers so a gel thickens.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    DependsFrizz-prone, damaged, or high-friction hair

    pH adjusters are how a formula is brought to a chosen acidity, and an acidic formula keeps the cuticle lying flatter than an alkaline one. Which way this one moves the pH depends on the formula, and the finished pH is not on the label.

    PubChem
    • pH adjuster
  • 5 Amodimethicone
    General function

    A silicone modified to stick where hair is damaged, so it smooths selectively instead of coating everything. It resists rinsing more than plain dimethicone.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitClimate-sensitive or frizz-prone hair

    A surface film slows how quickly humidity reaches the cortex, which is what limits swelling-driven frizz in damp air.

    May suitFrizz-prone, damaged, or high-friction hair

    Amino-functional silicone carries a positive charge, so it binds where the cuticle is worn rather than coating evenly. Damaged areas get most of it.

    May suitMaximum-hold styling

    Film formers are what hold a style: they dry into a connected film across the strands so the shape resists movement.

    International Journal of Trichology
    • silicone
    • conditioning agent
    • film former
  • 6 Fragrance · Parfum
    General function

    An undisclosed blend of scent ingredients. Regulations let it stay unlisted, so a fragrance-free product is the only way to be certain what is not in it.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    Declared fragrance. On a fragrance-sensitive routine this is the line that decides it, wherever it sits on the label.

    • fragrance
    • declared fragrance
  • 7 Phenoxyethanol
    General function

    The most common modern preservative; it keeps the product free of bacteria and mould. It sits well below 1% of the formula.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    PubChem
    • preservative
  • 8 Carbomer
    General function

    A thickener that turns a liquid into a clear gel. It also contributes a light hold.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitClimate-sensitive or frizz-prone hair

    A set polymer film is a physical barrier to humidity, so a style keeps its shape longer in damp conditions.

    May suitMaximum-hold styling

    Synthetic film formers dry into a continuous film, which is what holds a shape against movement and against humid air.

    DependsBuild-up-sensitive routines

    Some acrylate copolymers rinse with water and some need a detergent; the label alone does not say which one a formula used.

    • thickener
    • polymer
    • film former
  • 9 Polyquaternium-4
    General function

    A cellulose-based hold polymer used in gels and sprays for flexible set.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitCurls or waves needing flexible hold

    Cationic polymers hold a curl loosely and stay soft, which is why they turn up in definition products rather than firm-hold ones.

    May suitFrizz-prone, damaged, or high-friction hair

    A cationic polymer stays on the hair through rinsing, which is what keeps static and combing friction down after the wash.

    May suitMaximum-hold styling

    Film formers are what hold a style: they dry into a connected film across the strands so the shape resists movement.

    • conditioning agent
    • film former
    • polymer
  • 10 Potato Starch Modified
    General function

    A modified starch. It soaks up oil and water and leaves a dry, slightly grippy feel, which is what puts starches in dry shampoos and texture products.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitFine or easily flattened hair

    Adds grip and body with no oil attached, which is what lifts fine hair at the root instead of weighing it down.

    DependsMaximum-hold styling

    Starch gives texture and grip rather than a set film; firm hold usually needs a polymer alongside it.

    • starch
    • absorbent
  • 11 Limonene
    General function

    A citrus-smelling fragrance component that EU rules require to be named separately because some people react to it.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 12 Hydroxypropyl Guar
    General function

    A modified guar gum used to thicken and give a slippery, cushioned feel.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitCurls or waves needing flexible hold

    Gums thicken and set soft, which gives definition that bends rather than a rigid cast.

    May suitMaximum-hold styling

    A styling polymer dries into a film across the strands, which is what makes a shape hold instead of relax.

    • gum
    • thickener
    • polymer
  • 13 Behentrimonium Chloride
    General function

    A positively charged conditioning agent that binds to damaged, negatively charged spots on the hair. It is the main detangling ingredient in most rinse-out conditioners.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitFrizz-prone, damaged, or high-friction hair

    A cationic conditioning agent: it binds to the damaged, negatively charged parts of the cuticle and lowers combing friction there.

    DependsBuild-up-sensitive routines

    Substantive by design. A routine with no detergent wash gives it nothing to leave with.

    DependsVery dry or highly damaged hair

    Every detergent removes some sebum along with the product it is there to wash out. Which detergent it is matters more than that there is one.

    International Journal of Cosmetic Science
    • conditioning agent
    • cleanser
  • 14 Hydrolyzed Vegetable Protein PG-Propyl Silanetriol
    General function

    A plant protein modified to bind more firmly to hair than a plain hydrolysed protein. Used for strength and body claims.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitFrizz-prone, damaged, or high-friction hair

    Filling surface gaps evens out the cuticle, which is part of what makes damaged hair comb and reflect light more like undamaged hair.

    May suitMaximum-hold styling

    Film formers are what hold a style: they dry into a connected film across the strands so the shape resists movement.

    May suitVery dry or highly damaged hair

    Hydrolysed fragments are small enough to sit in the gaps of a worn cuticle for a wash or two, temporarily restoring stiffness and cutting breakage in combing.

    • film former
    • protein
    • hydrolysed protein
  • 15 Glycine
    General function

    The smallest amino acid in hair protein, added for moisture binding.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitVery dry or highly damaged hair

    Amino acids are the smallest protein fraction and bind water as well, so they add far less stiffness than a hydrolysed protein does.

    DependsProtein-sensitive hair

    The lightest option in the protein family, but still protein — worth watching if protein reliably stiffens your hair.

    PubChem
    • amino acid
  • 16 Trideceth-6
    • emulsifier
    • solubilizer
  • 17 Isopropyl Alcohol
    General function

    A fast-evaporating alcohol used as a solvent and to speed drying. Well down the list it is a processing aid; near the top it can leave hair feeling dry.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitFine or easily flattened hair

    Evaporates on contact, which is how a spray sets almost instantly and leaves no weight behind it.

    PubChem
    • drying alcohol
    • solvent
  • 18 Linalool
    General function

    A floral fragrance component listed separately as a recognised contact allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 19 Cetrimonium Chloride
    General function

    A quick-acting conditioning agent that reduces static and combing force. It also helps keep the formula stable.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May suitFine or easily flattened hair

    The C16 quat binds mostly by charge rather than by chain, so it deposits measurably less than the C22 ones. Less deposit is less conditioning and also less weight, which is usually the trade fine hair wants.

    May suitFrizz-prone, damaged, or high-friction hair

    A cationic conditioning agent: it binds to the damaged, negatively charged parts of the cuticle and lowers combing friction there.

    DependsBuild-up-sensitive routines

    Substantive by design. A routine with no detergent wash gives it nothing to leave with.

    International Journal of Cosmetic Science
    • conditioning agent
    • cleanser
  • 20 Citral
    General function

    A lemon-scented fragrance component listed separately as a recognised allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 21 Coumarin
    General function

    A sweet, hay-like fragrance component listed separately as a recognised allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 22 Benzyl Salicylate
    General function

    A soft floral fragrance component listed separately as a recognised allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 23 Sodium Benzoate
    • preservative
  • 24 Benzyl Alcohol
    • preservative
    • solvent
  • 25 Citronellol
    General function

    A rose-like fragrance component named separately as a recognised allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 26 Alpha-Isomethyl Ionone
    General function

    A violet-like fragrance component named separately as a recognised allergen.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    PubChem
    • fragrance
    • named fragrance allergen
  • 27 Potassium Sorbate
    • preservative
  • 28 Geraniol
    General function

    A rose-scented fragrance component, listed on its own because some people react to it.

    Estimated lower-concentration zone

    It appears around or below the estimated 1% line, where label order no longer indicates relative amount; its role may be minor or technical.

    May not suitFragrance-sensitive routines

    One of the 26 scent components the EU requires to be named individually above a threshold. It is named because it is a known contact allergen, not because it is unusual.

    • fragrance
    • named fragrance allergen

What the whole list adds up to

  • 9 fragrances
  • 8 named fragrance allergens
  • 4 film formers
  • 4 preservatives
  • 3 solvents
  • 3 polymers
  • 3 conditioning agents
  • 2 emollients
  • 2 silicones
  • 2 conditioning agents
  • 2 thickeners
  • 2 cleansers
  • 1 light ester
  • 1 pH adjuster

Ingredient list captured 2026-09-15. Formulas change, so check the package in your hand when an ingredient matters to you.

Price · 3.04 oz

Seen at $51.21 lowest of 2 stores · checked Oct 22
Good value under $24 Under $7.77/oz it costs less than three-quarters of the 8 products we score as doing the same job

Priced above the products that do the same job. Stores sell it above the $24 line; products that do this job typically go for about $30 at this size.

Show the price ladder
Where we’ve seen it3 listings · 3 stores

Sorted by price per ounce. Dated observations from our research, not live prices. Direct store pages, no affiliate links. We don’t sell this product.

How we work this out
  1. 3.04 oz is the size stores list most often; every comparison on this page is made at it. Other sizes are shown in the Sizes row and the store list.
  2. Seen at $51.21 is the price we have observed for the 3.04 oz. We need three stores before we call a price commonly seen.
  3. Good value under $24 comes from the 8 products we score as doing the same job as this one. A quarter of them cost less than $7.77/oz; at 3.04 oz that is $24. Under that line you are paying less than most of them.
  4. About $30 is what those same products typically cost at this size: the midpoint of their prices per ounce, scaled to 3.04 oz.

Formula

Formula score
6 of 10

We do not have enough heat protectants with a computable price per ounce to say where this one sits in the range.

How the score is counted
  • No stated heat claim in the formula
  • Prestige tier, sold at Salons and Brand website
  • Prestige tier
  • 2 sources consulted for this record
  • A film-forming heat spreaderSilicones or polymers that spread heat along the strand.3 pts
  • A stated heat claimThe brand names the protection it claims.2 pts
  • A light baseWater or a volatile carrier first, so it does not weigh hair down.2 pts
  • A humectantBinds water into the hair.1 pt
  • Slip for detanglingReduces the force it takes to comb wet hair.1 pt
  • Fragrance kept out of the top eightScent as a finishing touch, not a major share.1 pt

The formula score measures completeness for the job: a weighted share of the systems this product type is usually built around that we find in this list. It does not rate how well the product works or its quality, and it never compares across product types.

Does the same job

Formulas that do the same things (cleanse, condition, coat or hold) for less per ounce. Scent, texture and where you buy them can still differ.

KerastaseClosest function Résistance Extentioniste Thermique $10.20/oz
  • Protein-free
  • Medium weight
Function
  • Slip and detangling
  • Water-binding (humectants)
  • Protein
Also
  • 5.1 oz bottle
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KerastaseClose function Resistance Heat Protecting Leave-In Treatment for Split Ends $9.80/oz
  • Heat protect
  • Protein-free
  • Medium weight
Function
  • Slip and detangling
  • Water-binding (humectants)
  • Protein
Also
  • 5.1 oz bottle
  • Sold at specialty beauty counters
Compare
KerastaseLowest cost per oz Nutritive Nectar Thermique Beautifying Anti-frizz Blow Dry Milk $9.68/oz
  • Lightweight
· Close function
Function
  • Water-binding (humectants)
  • Weight on the hair
Also
  • 5.1 oz bottle
Compare

See more alternatives in the product library

These products do a similar job. We haven’t matched them to you. Find the one that fits your hair, routine and budget

Built for straight to curly hair

Final decision

Should you buy it?

Depends on your hair: see who it suits
Best user

Most hair types, looking for something that is neither heavy nor thin

Biggest tradeoff

Not ideal for anyone sensitive to fragrance, curly-method routines, or very dry or high-damage hair

Best alternative if not

Nothing in our library matches it closely at a lower price.

We do not sell products or take placement fees. This page states what the formula and the prices show; the consultation is what matches it to a person.

Claims check

What the brand says, and what the formula shows

Claims are quoted from the brand. We mark a claim supported, partly supported or conflicting only when the ingredient list speaks to it. Everything else stays "stated by the brand". That isn’t a criticism: most claims can’t be checked from a label.

1
SupportedBacked by ingredients
1
Partly supportedSome supporting logic
3
Stated by brandNo clear evidence
0
Potential conflictFormula works against claim
Protects hair from heat damage up to 450°F

Heat protection is a performance claim; an ingredient list cannot confirm it.

  • Dimethicone
  • Amodimethicone
  • Carbomer
Stated by brand

Only lab testing can show this.

Reduces appearance of split ends

Protein or ceramides are present, but low enough that this reads as support, not treatment.

  • Polyquaternium-4
  • Behentrimonium Chloride
  • Hydrolyzed Vegetable Protein PG-Propyl Silanetriol
Partly supported

Supports the surface, not a treatment.

99% stronger hair; 85% shinier hair

A brand-run study. We report it as stated and do not repeat the number as fact.

—

Stated by brand

Only the brand’s testing shows this.

Smooths frizz for up to 72 hours

Silicones or film formers smooth the cuticle, which is the usual mechanism.

  • Dimethicone
  • Amodimethicone
  • Carbomer
Supported

Smoother strands, less frizz.

Up to 3x smoother and 2x softer hair

A brand-run study. We report it as stated and do not repeat the number as fact.

—

Stated by brand

Only the brand’s testing shows this.

How to read this

We look at the first 10–15 ingredients and what they do in a formula, not at the marketing. If the list doesn't speak to a claim, we don't assume.

More from Kerastase

How this page was made

  • Everything above comes from our researched product record: identity, the ingredient list as printed, the brand's own claims, dated prices and review themes our researchers wrote in their own words. No part of this page is written by hand for one product.
  • The value band is a fixed label over two stored numbers: this product’s cost per ounce as a percentile of every product of this type we have priced, each at the size it is most often sold in, and how many products we score as doing the same job cost at least a quarter less per ounce.
  • Both scores out of ten are defined on this page. The formula score is completeness for the job, computed from a fixed per-format checklist shown beneath the gauge; the price score is cost per ounce against every product of this type we have priced.
  • The "Is this right for you?" panel reads only your own consultation answers, and it applies exactly the filters our recommendation engine applies. It is computed when you load the page and is never stored on it.
  • 2 sources consulted for this product (0 manufacturer or regulatory, 1 retailer, 1 editorial), last checked 2026-10-03.
  • Ingredient references are linked for 14 of 22 product-aware annotations on this page. Fit notes are general formulation guidance. They aren’t a verdict on the finished product or on you.
  • We haven’t tested this product in a lab, and we don’t physically test your hair. Formula readings come from the ingredient list. Claims about how it behaves are labelled as the brand's.
  • Ingredient order tells you relative amount only above roughly 1%. Prices are what we saw on the dates shown and can change.
  • Ingredient names link to our ingredient library, where each entry shows what it does, which product types use it, and where it usually sits on a label across everything we have researched.
  • This is cosmetic information, not medical advice, and nothing here diagnoses or treats a health condition.
  • Formula readings: derivation v23. Record last updated 2026-09-16.

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