Hormonal Changes in the Menstrual Cycle
Female hormones in the serum change cyclically according to the menstrual cycle in women.
Estrogen increases during the follicular phase of the menstrual cycle.
Progesterone increases during the luteal phase.
These changes in hormone levels can affect hair growth.
These hormones belong to the group of steroid hormones.
CYP19 gene encodes Aromatase
Some of estrogens are produced from androgens by the enzyme aromatase in the skin tissue.
Testosterone in the serum is modified to estradiol in the skin tissue by aromatase.
Most of the serum estrogen is produced in the ovaries.
The ovary is rich in aromatase (CYP19).
Aromatase is a complex of cytochrome P450, and it is produced by the CYP-19 gene.
Estrogen
It is still uncertain how estrogen affects hair growth.
Estrogen slows down the rate of hair growth.
Estrogen antagonists stimulate transmission from the telogen phase to the anagen phase. They induce the telogen phase to the anagen phase in the hair cycle.