Summer and scalp: what really happens under the sun

Sweaty skin, changing pH levels, irritation and free radicals: let's understand the mechanisms at work in summer and how to respond with the Estērel Method.

Why does the skin ‘change mood’ in summer?

When it is hot, the scalp increases perspiration and sebum production. Sweat (rich in salts) and sebum can alter the pH and hydrolipidic film, making the skin more reactive. Add to this salt, chlorine, wind and fine dust: a cocktail that can cause itching, redness, flaking, a feeling of ‘tight skin’ and more fragile hair.

The (often underestimated) role of free radicals

Prolonged exposure to UV rays generates free radicals (ROS) that trigger photo-ageing. This does not only affect the face: the scalp and follicles also suffer oxidative stress. Over time, hardening of the dermis (connective fibrosis), alterations in collagen and elastin and miniaturisation of the hair may occur: the hair appears finer, duller, less elastic and more prone to seasonal hair loss.

Signs not to be ignored

Feeling of “hot” or itchy skin after sun exposure.

Hair that gets dirty sooner (reactive hyper-seborrhoea).

Increased hair loss or perceived thinning.

Curly hair and lengths that are brittle or lose definition.

Respond methodically: the Estērel approach

The Estērel philosophy always starts with a diagnosis + targeted ritual to restore the skin's balance and protect the hair shafts. Here is a typical summer routine:

1. Rebalancing cleansing For those with shiny or sweaty skin, targeted cleansing helps remove impurities and sweat/salt residues without damaging the skin barrier. We recommend: the ‘Hair on Holiday’ kit for an essential ritual when travelling.

2. Sweat control + skin comfort Persistent sweating can worsen redness and itching. A specific “post-sun” treatment that refreshes and normalises the skin, supporting its physiological pH, helps to reduce irritation and prolong the feeling of cleanliness. We recommend: Phyto Sueur Lotion when sweating is excessive.

3. Antioxidant defence (UV & ROS) Taking antioxidants before/after exposure helps limit photo-ageing on skin and hair. The ESTĒREL Sun Collection stands out for its use of maritime pine extract, which is effective in combating the formation of free radicals, combining protection and prevention for skin and hair (as well as reducing phenomena such as discolouration and dryness).

4. Hair restructuring & strength After the sea and swimming pool, restoring moisture and elasticity to the lengths is crucial. For scalps and hair showing signs of premature ageing (stiffened dermis, thinned shaft), an anti-ageing focus can make all the difference. We recommend: Vital + Anti-Age² Lotion, formulated to combat connective fibrosis – one of the causes of hair loss linked to photo-ageing and chrono-ageing.

5. Smart routine when travelling When on holiday, simple gestures win: cleanse, protect, repair. An essential kit helps you maintain consistency without weighing down your beauty case. “Hair on Holiday” is perfect for enjoying your summer with peace of mind.

Practical tips (to save)

Before sun exposure: protect exposed skin (hairline, roots) and hair lengths with filters and antioxidants.

After swimming: rinse out salt/chlorine, patting without rubbing.

At home: alternate between gentle but effective cleansing and soothing/antioxidant treatments; incorporate nourishing masks.

Follow the signs: if you experience itching, burning or increased hair loss, reduce aggressive styling and switch to a “breathing + repair” routine.

Let's talk to our beauty scientists Every scalp has its own story.

If you want a personalised ritual (e.g. to assess whether to focus on Phyto Sueur Lotion or Vital + Anti-Age², or how to incorporate the Sun Collection into your routine), write to us: we will start with a diagnosis to build your programme, according to the Estērel Method.