Conseils
Scalp: anatomy, microbiome and complete routine for a healthy scalp
The scalp is skin in its own right: anatomy, microbiome, 4 profiles and complete routine (scrub, shampoo, serum) to restore its natural balance.
Scalp: anatomy, microbiome and complete routine
The scalp is not just a support. It is living, vascularized skin, inhabited by a microbiome and responsible for much of the beauty of your hair. Understanding it means finally choosing the right steps.
Key takeaways
- The scalp is skin in its own right, with epidermis, dermis, follicles, sebaceous glands and microbiome.
- Dandruff, itching, hair loss and oily roots often start on this scalp skin, not just on the fiber.
- A balanced microbiome depends on sebum, pH, the hydrolipidic film and the gentleness of the care.
- The ideal routine: Scrub every 10 to 15 days, Gentle Shampoo 2 to 3 times a week, Night Serum on the scalp.
Before trying to make the lengths shine, we start by rebalancing the foundation. A healthy scalp gives a more supple, more luminous and more resistant fiber over time.
The scalp care trio
The three key steps to exfoliate, clean without stripping and support the balance of the scalp.
The Scrub - Scalp exfoliating shampoo with organic hydrosols
Gentle exfoliation · scalp reset
- Micronized sea salt
- Active organic hydrosols
- Purifies without aggression
The Shampoo - Organic hydrosols and hyaluronic acid
Gentle cleansing · 98% natural
- No sulfates or silicones
- Cationic HA
- 3 plant proteins
The anti-hair loss & thickening Night Serum with probiotics
Microbiome · density
- Probiotics and postbiotics
- Roots and scalp
- 3 to 5 evening treatment course
What is the scalp? Anatomy and physiology
The scalp is the portion of skin covering the skull, from the forehead to the nape. Like the rest of the skin, it is composed of three layers: the epidermis, the dermis and the hypodermis.
On this surface, we find an impressive density: between 150 and 300 hair follicles per cm² depending on the hair type and ethnic origin, i.e. a total of 100,000 to 150,000 hairs on average.
To better understand the anatomy and physiology of the scalp, we must look at the follicle as a small factory: it produces the fiber, receives the sebum, communicates with the microbiome and depends on microcirculation.
The visible barrier, directly exposed to shampoos, hard water, friction and styling products.
The active zone: blood vessels, nerve endings, hair follicles and sebaceous glands.
The deep layer, more fatty, which participates in supporting the skin of the skull.
The pilosebaceous follicle, basic unit of the scalp
Each hair grows from a pilosebaceous follicle, a structure composed of the hair follicle, the sebaceous gland and the arrector muscle. This architecture explains why an unbalanced scalp directly impacts the quality of the hair.
The hair cycle: anagen, catagen, telogen
| Phase | Average duration | What happens | Why it is important |
|---|---|---|---|
| Anagen | 2 to 6 years | Active growth phase. | The longer it lasts, the longer and denser the fiber can be. |
| Catagen | 2 to 3 weeks | Transition phase, the follicle retracts. | The hair prepares to leave its active phase. |
| Telogen | About 3 months | Rest phase then natural fall. | 50 to 100 hairs per day can fall without warning. |
The scalp microbiome: the invisible balance that changes everything
The scalp hosts its own microbiome: an ecosystem of bacteria and yeasts that lives in balance with the sebum and the pH of the skin. It is this invisible terrain that influences comfort, dandruff, irritation and the quality of the growth cycle.
Lipophilic yeast nourished by sebum. It becomes problematic when it proliferates too much.
Bacteria that participates in maintaining a protective acidic pH.
Protective microorganism that limits certain unwanted germs.
The pH, conductor of the balance
A healthy scalp shows an acidic pH, between 4.5 and 5.5. As soon as the pH rises above 6, often due to a shampoo that is too alkaline or hard water, Malassezia proliferates more easily, the sebum oxidizes and discomfort can increase.
Sebum and microbiome: a two-way dependence
Sebum is not the enemy. It is the food of the beneficial microbiome. The problem arises when there is too much or not enough. In both cases, microbial diversity drops and opportunistic species take over.
This is the whole logic of our formulas based on active organic hydrosols: to clean and hydrate without stripping, in order to respect the hydrolipidic film and support the natural balance of the scalp.
The 4 types of scalp: oily, dry, sensitive, normal
Before choosing a routine, you must know what profile you are dealing with. Here is how to distinguish them quickly.
Hair that regreases in 24 to 48h, flat roots, shiny appearance from the day after shampooing.
Tightness, small dry dandruff, dull or brittle lengths.
Itching, tingling, redness at the level of the parting, reactions after certain products.
Neither quickly oily nor dry, no particular discomfort. The goal is to maintain this balance.
The simple test: observe your scalp 48h after a gentle shampoo, without styling product. If it shines and sticks to the fingers, it is oily. If it pulls and flakes in fine particles, it is dry.
Common problems: dandruff, itching, irritation, hair loss
The dandruff and scalp imbalance often result from a proliferation of Malassezia, which transforms sebum into irritating compounds.
They are often linked to an unbalanced pH, a weakened skin barrier or an intolerance to sulfates, silicones or synthetic fragrances.
A scalp microbiome that is durably unbalanced can maintain local inflammation and discomfort, which weakens the growth foundation.
Complete routine for a healthy scalp
An effective routine follows a simple logic: exfoliate, clean gently, then bring targeted actives to the fiber and the scalp, without ever breaking the pH or the microbiome.
Step 1 - Detoxifying scalp scrub
A scalp scrub removes dead cells, oxidized sebum residues and the accumulation of styling products, without aggressing the skin of the skull.
Frequency: every 10 to 15 days depending on needs.
Step 2 - Sulfate-free shampoo with hydrosols
The cleansing must breathe without stripping. The goal is to clean the scalp, not to deprive it of its hydrolipidic film.
Frequency: 2 to 3 shampoos per week, up to 4 on oily scalp if the formula remains gentle.
Step 3 - Targeted Night Serum
This is the step that many routines forget: a leave-on care applied part by part, directly on the scalp.
Frequency: daily or 3 to 4 evenings per week depending on the need.
The principle that changes everything: the scrub exfoliates, the shampoo cleans, the serum supports the balance. It is this complementarity, and not a single miracle product, that gives back to the scalp its self-regulation capacity.
Errors that unbalance the scalp
Some reflexes, although very widespread, sabotage the balance of the scalp without us realizing it.
When to consult a dermatologist
A cosmetic routine, even well constructed, has its limits. Some signals should lead you to consult a dermatologist or a doctor, without waiting.
A loss that greatly exceeds 100 hairs per day over several weeks, or areas without hair, requires a medical opinion.
These signs can evoke seborrheic dermatitis, psoriasis or another scalp pathology.
If the discomfort does not improve after 3 to 4 weeks of gentle routine, you must look for a medical cause.
A painful scalp or one with lesions is not merely a cosmetic issue.
FAQ - Your questions about the scalp
What is the scalp?
How large is the scalp?
What is the scalp microbiome?
Oily or dry scalp, how to tell the difference?
Why does my scalp get oily again so quickly?
Are dandruff contagious?
What is the difference between dandruff and seborrheic dermatitis?
How often should the scalp be exfoliated?
Is sebum bad for the scalp?
When does hair loss become worrying?
Sources
- Medical Encyclopedia - Hair follicle, Wikipedia: fr.wikipedia.org/wiki/Follicule_pileux
- French Society of Dermatology - Structure and skin appendages: sfdermato.org
- ORBi University of Liège - Squamous conditions of the scalp and dandruff: orbi.uliege.be
- PubMed - Comparison of Healthy and Dandruff Scalp Microbiome Reveals the Role of Commensals in Scalp Health: pubmed.ncbi.nlm.nih.gov/30338244
- PubMed - The pH of the skin surface and its impact on the barrier function: pubmed.ncbi.nlm.nih.gov/16864974
- EUR-Lex - Regulation (EC) No 1223/2009 on cosmetic products.
