Kerastase: What It Is, Why It Works, and Where to Start

If your hairdresser has ever recommended Kerastase - or you have noticed it in salons and wondered if it is worth the price - this guide answers every question you have. What it is, what makes it different, how to find the right range for your hair, and which products are genuinely worth starting with.

What Makes Kerastase Different from Regular Haircare

Kerastase is a professional haircare brand formulated to the same standards as salon treatments. That means higher concentrations of the active ingredients that actually do something - proteins, ceramides, amino acids, treatment actives - and lower levels of water and filler. The result is a product that works faster and lasts longer than most consumer alternatives.

The formulation difference

Most supermarket shampoos are roughly 80% water with a small amount of cleansing agent and fragrance. Professional brands like Kerastase reverse the ratio of active-to-filler ingredients - which is part of what you are paying for, and why the results tend to be visible from the first use rather than accumulating over weeks.

Why concentration matters in practice

A simple analogy: you can make a cup of tea with one teabag or four. Both are technically tea. One delivers noticeably more. The same logic applies to haircare actives. Kerastase puts more of the ingredient that actually repairs, nourishes, or smooths into each bottle - which is why a smaller amount of product delivers a more visible result.

A Plain-English Guide to the Kerastase Ranges

Kerastase has multiple ranges, each targeting a specific hair concern. The hardest part of buying it for the first time is knowing which range applies to you. Here is a plain-English breakdown.

Genesis - for hair fall, thinning, and scalp health

Genesis is Kerastase's answer to hair thinning, excessive shedding, and scalp health - and it is the range that generates the most search interest in Australia. The range addresses hair fall from breakage and mechanical stress (combing, styling, processing), not hormonal or medical hair loss. If your shedding is significant, pairing a Genesis routine with a dermatologist visit is worthwhile.

Gloss Absolu - for glass hair, shine, and frizz control

Gloss Absolu is Kerastase's shine-focused range and one of the most commercially strong ranges in the current lineup - particularly relevant as glass hair continues to trend. The range targets dull, frizzy, or texture-prone hair and uses a glaze-based technology to smooth and reflect light. The Glaze Drops hair oil is consistently one of the highest-reviewed products in the entire Kerastase range, and the Gloss Absolu Oil Trio Coffret is a strong gifting and self-treat option.

Nutritive - for dry and dehydrated hair

If your hair feels dry, rough, or dull - not from damage, but simply from dehydration - Nutritive is the starting point. It is built around replenishing moisture and restoring softness. The Bain Satin shampoos and the Masque Nutritive are the workhorses, and the Nutritive 8h Magic Night Serum is the standout hero product - more on that below.

Resistance - for damaged and weakened hair

If your hair has been heat-styled, chemically treated, or over-processed to the point of breakage or visible damage, Resistance targets structural repair using proteins and amino acids to reinforce the hair fibre from within.

Blond Absolu - for blonde and lightened hair

Designed specifically for chemically lightened hair, Blond Absolu protects and strengthens the hair fibre while minimising brassiness. The Anti-Brass Purple Shampoo (1,181 reviews) and Cicaextreme Mask are standout products.

Discipline and Curl Manifesto

Discipline uses Morpho-Keratine Complex to smooth frizz-prone hair for longer-lasting sleek results. Curl Manifesto is the newest major addition to the lineup and has quickly become a favourite among curl communities for hydrating and defining without weight.

How to Find the Right Kerastase Range for Your Hair

By hair concern

Dryness without damage: Nutritive. Visible breakage or chemical damage: Resistance. Hair fall and thinning: Genesis. Frizz, dullness, and desire for glass hair shine: Gloss Absolu. Blonde or lightened hair with brassiness: Blond Absolu. Frizz from humidity: Discipline. Curly or wavy patterns: Curl Manifesto.

By hair type

Fine hair should start light - the Genesis Bain Hydra-Fortifiant for thin hair or the Nutritive Lait Vital (lightweight milk conditioner) rather than heavier mask formulas. Thick or coarse hair can handle richer formulas. Colour-treated hair benefits from Blond Absolu if lightened, or a colour-safe formula within the relevant concern range if tinted.

The Products Most Worth Starting With

The overnight treatment that 4,584 customers recommend

The single most reviewed Kerastase product on the Oz Hair and Beauty site is the Nutritive 8h Magic Night Serum. It is an overnight leave-in treatment - applied to dry or damp hair before bed, combed through the mid-lengths and ends, and left in overnight without rinsing. In the morning you wake up to noticeably softer, smoother, shinier hair. It is lightweight and non-greasy despite the concentrated formula, and it is suitable for all hair types. If someone asks you where to start with Kerastase, this is a compelling first product: the result is visible from the first use, the concept is simple (do it before bed, wake up to better hair), and the review volume speaks for itself.

The Gloss Absolu oils: for glass hair results

If the result a customer is chasing is high-shine, glass-hair smoothness, the Gloss Absolu Glaze Drops Hair Oil is the entry point. It delivers an intense shine and smoothing finish that works both as a treatment and a styling product. The Anti-Frizz Glaze Milk All-In-1 Spray is the versatile everyday option - heat protectant, detangler, and shine booster in a single step. For someone who wants the full glass hair experience, the Gloss Absolu Oil Trio Coffret is one of the best value bundles in the range with 5,477 reviews.

The Genesis serum: what it does and who it is for

The Genesis Anti-Breakage Fortifying Serum is one of the most searched Kerastase products in Australia for good reason - it addresses hair fall from mechanical stress and breakage rather than just conditioning the surface. Applied to the scalp and hair lengths, it fortifies from root to tip and is designed to be used as part of the Genesis system (alongside the shampoo and conditioner) rather than in isolation. Results are cumulative over several weeks of consistent use.

Getting the Most From Kerastase

The right amount to use

Most people use too much. With a concentrated professional formula, a small amount goes further than you expect. For shampoo: a 10-cent coin-sized amount for short-to-medium hair. For the Night Serum: 2 pumps for fine hair, up to 4 pumps for thick or long hair. For conditioners and masks: focus on mid-lengths and ends - applying to the roots adds weight without benefit.

Layering for better results

The Kerastase system is designed to layer - a shampoo from the range prepares the hair for the conditioner, which prepares it for any serum or treatment. Using the Night Serum on hair washed with a Kerastase shampoo consistently gives better results than using it over a drugstore wash. Using the full range from the same line gives the most noticeable cumulative result over time.

Kerastase vs Other Premium Brands

Kerastase vs Olaplex

These brands target different problems and both are genuinely excellent. Olaplex was built specifically around bond repair - restoring the disulfide bonds broken by bleaching and chemical processing. Kerastase has its own bond repair technology within the Resistance range, but its broader strength is range depth - there is a specifically formulated range for almost every hair concern, not just chemical damage. Many customers use both: Olaplex for bond repair after colour services, Kerastase for their ongoing daily routine.

Kerastase vs Redken

Both are owned by L'Oreal and both are professional-grade. Redken tends to be slightly more accessible in price with strong roots in colour care. Kerastase is the premium tier - richer formulations, more targeted ranges, and a heavier focus on treatment-grade results. Customers who want the best daily haircare routine typically land on Kerastase; customers who want excellent colour maintenance often start with Redken.