What shampoo is and what it's for
Shampoo is the base product of any hair care routine: its function is to cleanse the scalp and hair fibre by removing excess oil, product residue and dirt particles that build up day after day. Beyond cleansing, a good shampoo prepares the hair to better absorb the rest of the treatments applied afterwards, such as conditioner or a hair mask, so choosing the right formula directly influences the final result of the whole routine.
Not all shampoos serve the same purpose: some are designed just to cleanse, others also provide volume, hydration or colour protection, and others are specifically formulated for scalps with particular needs, such as sensitivity or a tendency towards oiliness.
pH also plays an important role: the scalp naturally has a slightly acidic pH, and formulas that respect this balance help maintain the skin's protective barrier and keep the hair cuticle closed, resulting in smoother, shinier looking hair after washing.
How to choose a shampoo according to your hair type
The choice should be based on the condition of the scalp and hair fibre, not just on the aesthetic result you're looking for:
- Oily hair: deep-cleansing, lightweight formulas that don't overload the roots or leave a heavy feeling.
- Dry hair: creamy shampoos with nourishing ingredients that cleanse without drying out the fibre any further.
- Combination hair: balancing formulas that regulate the roots without neglecting hydration at the ends.
- Fine hair or hair lacking body: volumising shampoos with lightweight textures that don't weigh hair down.
- Coloured hair: gentle formulas that help preserve colour and not speed up its fading.
The scalp also deserves attention of its own: if it tends towards sensitivity or dryness, it's best to prioritise gentle formulas without strong fragrances, while an oily-prone scalp benefits from shampoos formulated for a deeper, more frequent cleanse.
Types and formats of shampoo
In addition to conventional liquid shampoos, there are bar formats, designed to reduce packaging and concentrate the formula, and powder or dry shampoos, which absorb excess oil between washes without the need for water. There are also shampoos for specific uses, such as clarifying ones, which remove product build-up, or those for very frequent use, formulated to allow daily hair washing without drying it out.
Ingredients to keep in mind
Surfactants are responsible for cleansing and vary greatly in gentleness: sulphates cleanse deeply but can be harsh on sensitive scalps, while gentler alternatives exist for delicate skin and hair. It's also common to find ingredients like salicylic acid or green tea extract in formulas for oily hair, and oils like argan or shea butter in shampoos for dry hair. Volumising shampoos often include lightweight proteins and polymers that coat the hair fibre to give it body, while those formulated for coloured hair include filters that help slow colour oxidation caused by light.
How to apply shampoo correctly
Ideally, shampoo should be applied to the scalp, not directly onto the lengths, and massaged in with your fingertips to boost circulation and carry dirt towards the rinse. The product, already diluted by the massage itself, sufficiently cleanses the ends during rinsing, so there's no need to apply more there. A second wash is only necessary if the hair is very dirty or a lot of styling product has been used.
Common mistakes when choosing or using shampoo
- Using an oily-hair shampoo along the entire length, which can dry out the ends.
- Changing shampoo too frequently without giving it time to show results.
- Applying excessive amounts of product, which makes it harder to rinse out completely.
- Not adjusting washing frequency to the scalp's actual needs.
Choosing the right shampoo and applying it correctly is the foundation on which the rest of your hair care routine is built.
