Women in particular experience many hormonal changes during their lifetime, sometimes having an impact on hair health.

From pregnancy until menopause, throughout their existence women undergo hormonal changes which have many effects on their body. Hair loss, or on the contrary, rapid growth, is among the effects of these hormonal changes.

Hair loss, a stage in the hair's life cycle

To fully understand how hormonal changes can impact hair loss, you must first understand the life cycle of the hair. This consists of three main phases:
• the anagen phase, during which the hair grows about 1 mm every three days;
• the catagen phase, a period of transition characterised by a certain stability;
• the telogen phase, during which a new hair bulb develops, pushing the existing hair to detach from the follicle, leading the existing hair to fall out.

The duration and intensity of these two phases are likely to vary according to the hormonal situation of human beings, and particularly of women.

The role of estrogen in your hair health

Two main types of hormones influence the telogen and anagen phases of hair: androgens and estrogens. Although these two hormones are present in both men and women, they are not distributed in the same way.

Androgens – male hormones – are present in greater quantities in men. They accelerate the life cycle of hair and can cause premature hair loss.

Estrogen, on the other hand, is present in greater quantities in the body of women and promotes hair growth.

Women are therefore, in theory, less prone to hormone-related hair loss. However, the hormonal disturbances that they undergo during their lifetime can upset this state of affairs, and the balance between the anagen and telogen phases:

• 85% of hair in the anagen phase and 15% in the telogen phase in a normal situation;
• 95% in the anagen phase and 5% in the telogen phase during pregnancy, when estrogen levels skyrocket;¹
• 79% in the anagen phase and 21% in the telogen phase 4 months after childbirth;¹
• Acceleration of the anagen phase towards the telogen phase during menopause, with the drop in estrogen levels. ³

Other hormonal changes that effect your hair

Beyond fluctuations in estrogen levels, responsible for hair loss in women, other phenomena can also impact the health of your hair.

Thyroid problems and hair loss

The thyroid, a small gland at the base of the neck, secretes a series of hormones that keep your hair healthy. However, when this gland is disregulated (hyperthyroidism, either too many hormones produced, or hypothyroidism, not enough hormones produced), several effects can be observed in your hair:
- hair loss;
- weaker hair;
- more oily or on the contrary drier hair.

To resolve this issue, there are treatments using a specific dosage. Ask your doctor to find out more.

PCOS (polycystic ovarian syndrome) and hirsutism

PCOS (Polycystic Ovarian Syndrome) is a hormonal imbalance leading to excessive testosterone production in women. This phenomenon has the effect of increasing hair growth on normally hairless areas (hirsutism), and also causing hair loss, as in men (androgenetic alopecia).

Here too, hormonal treatments make it possible, in certain cases, to rebalance the situation. This disease, which affects one in 10 women, often leads to more serious complications (infertility, diabetes, endometrial cancer, cardiovascular disease, etc.).