Estrogen is related to hair growth — and hair loss. During pregnancy, for example, a woman's estrogen levels are higher than normal, which signals more hair follicles to "grow" and fewer to "rest." While estrogen levels are high, women have full, thick hair.
But while testosterone is at the core of the balding process, dihydrotestosterone (DHT) is now thought to be the main culprit. DHT, a derivative of the male hormone testosterone, is the enemy of hair follicles on your head. Simply put, under certain conditions DHT wants those follicles dead.
While estrogen can help thin hair, it cannot completely reverse facial and body hair growth.
When the levels of estrogen and progesterone drop, hair grows more slowly and becomes much thinner. A decrease in these hormones also triggers an increase in the production of androgens, or a group of male hormones. Androgens shrink hair follicles, resulting in hair loss on the head.
Estrogen Excess
Just like excess testosterone and excess DHT can cause hair troubles, so can too much estrogen. For some women, excess estrogen may trigger hair loss because of a gene variant that affects the functioning of an enzyme (aromatase) that processes estrogen.
With that said, one of the physical changes that accompany estrogen hormone replacement therapy is body and facial hair thinning. Those on estrogen GAHT (both estradiol and anti-androgens and/or progesterone) can experience hair thinning on the face, chest, abdomen, legs, and arms.
During menopause, a woman's body stops circulating estrogen but continues to circulate the same amounts of testosterone. The imbalance of hormones causes the appearance of some male secondary sex characteristics, like coarse facial hair.
As with male pattern baldness, female pattern baldness comes from hormone imbalances, specifically dihydrotestosterone imbalances, or DHT. This hormone is similar in structure to testosterone, but it is significantly more potent [3]. DHT can attach to receptors on the hair follicles, causing the follicles to shrink.
Androgens stimulate more visible body hair during puberty (e.g., beard) and continue increasing various hair follicle and hair sizes for many years (3).
The female sex hormone oestrogen makes body hair fine and soft. Androgens are male sex hormones, including testosterone, which are responsible for masculine characteristics such as facial hair and coarse body hair. A woman's ovaries and adrenal glands naturally make a small amount of androgens.
Estrogen has been postulated to aid hair growth by extending the anagen phase of the hair growth cycle [32], during pregnancy, for example [6]. In the postpartum period, an increase in number of hairs in the telogen phase results in increased hair shedding [5, 6, 24].
High estrogen levels can cause symptoms such as irregular or heavy periods, weight gain, fatigue, and fibroids in females. In males, they can cause breast tissue growth, difficulty getting or maintaining an erection, and infertility.
Even a slight increase in androgen or imbalance between your male and female sex hormones — which everyone has — can result in more terminal hairs in places you may not expect, like your chin.
For women, the hair may grow in areas where men often have a lot of hair, but women often don't. This includes the upper lip, chin, chest, and back. It's caused by an excess of male hormones called androgens. All women naturally produce small amounts of androgens.
Both stress and excess fat can lead to increased androgen production. Prevention is ideal because once facial hair is present, reduction techniques such as laser hair removal, IPL (Intense Pulsed Light), or electrolysis are the only ways of achieving permanent removal. Waxing is also an option, though only temporary.
Too little estrogen can lead to a low sex drive. Too much of it can cause infertility and erectile dysfunction. Excessive estrogen can cause gynecomastia, or enlarged breasts.
Estrogen promotes the storage of fat for healthy reproductive years. When estrogen is balanced, the right amount of fat helps carry out female reproductive functions. However, when there's too little or too much estrogen, weight gain often results.