Hair gloss: what is this technique that makes hair shine?

Hair gloss is a semi-permanent colouring technique designed to subtly alter the colour while enhancing the shine of the hair fibre.

Unlike an colouring of oxidation, which lifts the cuticle scales and alters the internal pigments, gloss relies on an acidic formulation in which the pigments deposit on the surface, between the cuticle scales, without penetrating the cortex. As a reminder, each hair fibre is structured in three superimposed layers. The outermost layer, the cuticle, consists of keratinised scales that fit together like roof tiles and serve as a protective barrier. Beneath this covering lies the cortex, the thickest part of the hair, rich in keratin and pigments. The cortex is responsible for the hair’s mechanical strength and its colour. Finally, the medulla forms the central core but plays little part in the hair’s physical properties.

The absence of oxidation in hair gloss accounts for its mildness: the hair is not sensitised, and the resulting shade fades gradually, like a tan, without leaving any demarcation. Hair gloss formulations typically include cationic agents that bind electrostatically to the fibre to smooth, detangle and temporarily strengthen the lengths, as well as moisturising agents that enhance the hair’s optical quality. This technique also differs from glazing, which uses mildly oxidising agents that can weaken the hair if applied too frequently. Hair gloss thus positions itself as an intermediate alternative: sufficiently pigmented to enhance a hue or correct an undesired tone, yet gentle enough to suit both natural and coloured or sensitised hair.

Hair gloss is a highly popular treatment among those seeking to enhance their hair without causing damage. Thanks to its semi-permeable formula, it enables to intensify an existing tint, to introduce a nuance or, conversely, to neutralise an unwanted tone, such as yellow, golden or copper hues, frequently observed after bleaching or a sun exposure prolonged. Hair gloss can also warm or cool a colour, subtly darken hair by up to two levels, or even impart a fresh sheen to the hair. It may also be used to conceal the first grey hairs, blending them into the bulk and softening an overly pronounced balayage to restore a more natural appearance. Highly useful for correcting visible regrowth, gloss is also suitable for coloured hair or for those hesitant to take the plunge and opt for highlights.

Hair gloss has an ephemeral nature which, depending on the point of view, may be considered either an advantage or a disadvantage. In fact, its effects persist for six to ten weeks.

A systematic review of 22 studies published between 2010 and 2023, involving around 1,000 volunteers, analysed 150 hair gloss products and confirmed their value. Although the results, presented below, are subjective and solely reflect participants’ perceptions, they nonetheless offer important insights and demonstrate the overall satisfaction of hair gloss users.

As mentioned above, a hair gloss is a semi-permanent hair colour formulated to deposit pigments on the hair surface. It relies on gentle chemistry, characterised by an acidic, ammonia-free formulation. This acidity allows the cuticle scales to tighten, which enhances light reflection and explains the distinctive shine achieved after treatment.

More precisely, the pigments present in a gloss bind between the cuticles through weak interactions (hydrogen bonds, van der Waals forces), which explains the temporary nature of its hold. As it does not alter the hair’s internal chemistry, hair gloss cannot lighten it; it can only darken it slightly or neutralise unwanted reflections. Hair glosses also contain a cationic complex, that is to say positively charged molecules that are able to adhere to keratin, a molecule which is negatively charged. This promotes an immediate conditioning effect.

Did you know? Cationic agents are also present in conditioners and hair masks, which are responsible for the conditioning effect of these hair care treatments.

A hair gloss treatment follows a simple yet methodical protocol. It can be carried out in a salon or at home.

When hair glossing is performed in the salon, it all begins with a assessment of the desired colour and the condition of the hair fibre (porosity, split ends...). This stage is critical, as not all glosses serve the same purposes, particularly when it comes to neutralising or intensifying colour reflections. It is also at this point that the colourist chooses between a single gloss (one shade) or a double gloss (two shades), used to blend the roots, correct an overly contrasted balayage or naturally disguise grey hair.

The gloss is then applied to slightly damp hair. The semi-permanent formula is distributed evenly across the entire hair or solely on specific sections. The hairdresser ensures that the lengths are uniformly saturated. The processing time generally varies between 10 and 30 minutes, depending on the shade, the porosity and the desired outcome. The gloss is then rinsed thoroughly, followed by an acidic treatment or conditioner designed to stabilise the shine and prolong the result’s longevity. The hair is then dried. This step instantly reveals the shine achieved thanks to the hair gloss.

Note : Hairdressers typically recommend a hair gloss treatment every three months, but it can be carried out every 5 to 6 weeks to maintain the results.

It is also possible to perform a hair gloss treatment at home, but the results are often less satisfactory. Indeed, beyond the products used—which are generally of superior quality in salons—professional stylists possess far greater technical expertise: choosing the gloss shade according to the hair’s underlying tone, calibrating the neutraliser dosage, adjusting processing time to the fibre’s condition and applying the product evenly, strand by strand. At home, even with a reputable product, these parameters are much harder to control, which explains the sometimes uneven results, variable shine and reduced durability.

Although it adds shine and highlights, hair gloss has certain limitations that are important to understand before you begin. Its effect is short-lived: the lustre usually diminishes after six to ten weeks, depending on fibre porosity, wash frequency and the products used. Furthermore, if you wish to apply a gloss to mask your grey hair, do not expect them to be completely concealed : this technique simply reduces their contrast and blends them into the base shade.

In terms of precautions, we recommend performing a patch test, as although hair gloss contains fewer oxidising agents than a conventional hair colour, it can still provoke reactions in sensitive individuals, notably irritations or allergic reactions. You should also avoid applying a hair gloss that is too dark on highlighted or lightened hair, as this may produce a dull or slightly greenish sheen. Finally, for those wanting to apply hair gloss at home, it is important to follow the usage instructions precisely, as overly long application or uneven distribution can result in an irregular finish. In a salon, the hairdresser adjusts both formula and technique, thus minimising these risks.

• BONTOZOGLOU C. & al. In vivo human hair hydration measurements by using opto-thermal radiometry. International Journal of Thermophysics (2018).

• RIBEIRO A. & al. Biotechnology of functional proteins and peptides for hair cosmetic formulations. Trends in Biotechnology (2022).

• MEHRA S. BH12 Efficacy and safety of hair gloss treatments: A systematic review of licensed products in the UK. British Journal of Dermatology (2025).