Hair is a component of human hair, more or less spread over the top, sides and back of the head. Like other integuments, it is composed of keratin.

Hair does not grow continuously but in a cyclical and periodic rhythm which can vary according to the individual, his age and the seasons.

The phases of growth (anagen phase), regression (catagen phase) and rest (telogen phase) follow one another. This last phase results in death and hair loss, followed by new growth.

The first cycles begin as early as the fifth month and a half of fetal life and continue throughout life or until the loss of the last hair.

In women, the length of the growth cycle is 4 to 7 years, compared to 2 to 4 in men. Hair grows faster in women than in men3.

The hair is divided into two parts:

the root, which is the invisible, living part; and the hair shaft, which is the visible, biologically dead part, made up like the hair of three parts: the cuticle, the cortex and the medulla (or marrow). A hair does not fall until 2 to 3 months after the death of the cell which produces it (spontaneous or pathological), this period being shortened under the influence of mechanical factors (traction, friction, shampooing).

Dead hair has a full, atrophied, white, dry bulb, which is sometimes mistakenly believed to be a "root" that cannot be replaced.

The speed of hair growth varies with age and seasons but also with a hereditary component. It is on average 0.7 to 2 cm per month, with straight hair generally growing faster than average and frizzy hair less quickly.

In a lifetime, we can therefore produce about 10 m of hair, or 1000 km end to end.

Multiple causes, physiological and pathological, can modify this evolution.

Male hormones, which determine the abundant growth of so-called male hair (beard, mustache), on the other hand, have an inhibitory action on hair growth, which explains the frequency of alopecia in men, as well as in subjected women. androgenic hormone therapy.

In Antiquity, it had already been noted that eunuchs were never bald. The importance of testosterone as a factor in hair loss has since been shown.

Hair loss We lose on average between 30 and 60 hairs per day but this figure can go up to a hundred per day.

Hair loss is not just the result of stress or an unbalanced diet.

The causes of hair loss can be both external and internal.

They can be divided into two categories:

androgenetic alopecia also called baldness (a form of hair loss with a genetic and hormonal cause) and telogen effluvium also called diffuse baldness (frequent hair loss, caused by an organic disorder).

The genetic causes of hair loss are usually permanent, while the non-genetic causes are temporary.

The most frequently used treatments to slow hair loss naturally ....