Older men can seem to have large eyebrows and a lot of ear hair. They also have substantial sniffer strands. Many men lose their hair on the top of their heads. However, some people's eyebrows, nose and ear hairs look like they have been immersed in magical growth elixirs.
Women's hair, including their eyebrows tend to get thinner as they age. Hence, why does the appearance of facial hairs in men age more bushy than that of women?
High hormone levels, namely testosterone, can have an impact on the hairiness of older men. According to Dr. Danilo de Campo, a Chicago Skin Clinic dermatologist, these hormones have a greater effect on hair follicles with age. According to a 2020 review published in the International Journal of Molecular Sciences, estrogen, which is responsible for increasing hair diameter and growth, tends to decrease after menopause.
Related: Why are eyebrows and eyelashes important?
Dr. Marie Jhin, President of Premier Dermatology San Carlos, California, stated that hair growth, speed, texture, and color depend on genetics, age, nutrition and health.
Del Campo stated that hormones and their responses are key reasons for hair differences between men and women as we age.
How to grow eyebrow hairs
Hair follicles are the source of all hair growth. The life cycle of hair follicles has three phases. There is the anagen phase, the catagen phase and the telogen phase. According to the 2020 review, hair eventually falls out after follicles have gone dormant. This is sometimes called the "exogen phase". The anagen phase is where the process begins again.
Because the lengths of different phases are different, hairs grow in different areas of the body. Del Campo stated that the anagen phase of hair on the scalp is the longest, with a typical length of between two and seven years. He explained to Live Science via email that eyebrow hairs and other hair-bearing areas are quite different.
The anagen phase of a hair follicle is shorter, which means that the length of hairs in that area are shorter when they go dormant. Del Campo stated that eyebrows have a short anagen phase, which lasts for about 30 days. The short growth phase is followed by a longer resting phase. This explains why eyebrow hairs typically measure 0.4 inches (1 cm) or less.
"If the anagen period was longer, people would have to use scissors at their barber very often to trim their eyebrows," Del Campo stated. Grooming requirements become more important for some men as they get older.
The role of Testosterone
Hormones in the body influence the length of each phase. Jhin explained that hormones can greatly affect the hair cycle and the structure of the hairfollicle. Men are more likely to have higher levels of androgens (especially testosterone) than women. She explained that men's hair grows faster because of these androgens.
According to the 2020 review, these androgens control hair growth during puberty. Jhin stated that these androgens are responsible for stimulating the growth of hairs in sex-specific areas, such as the pubic, chest and face, and the axillary [armpits] area during puberty. They act as stimulation for the hairs.
Related: How fast can hair grow?
Jhin says that as men age, hair follicles become more sensitive to certain hormones. The hormones help to keep the hair follicles in the anagen phase for longer periods of time, making them more sensitive to androgens. This leads to increased hair growth in areas such as the nose, eyebrows, and ears.
Jhin says that hair follicles in the scalp react to testosterone differently, which can cause them to grow slower when testosterone levels rise. This is why older men may have hirsute eyebrows and long nose hairs. They also have tufty ears and a balding head.
Del Campo stated that men's eyebrows tend not to shrink until they are older (this also applies to the ear and nose hairs). "Women have lower levels of testosterone."
As women age, estrogen levels drop during menopause . According to the 2020 review, lower estrogen levels and other hormone factors and changes in older age are believed to cause thinner and less dense hair. Jhin stated that while men still produce androgens up to age 70s, women's hormones are depleted around 50.
Original publication on Live Science
