(Another fun fact: While men experience their thickest hair in their 20s, many women experience their thickest head of hair in this decade.)
Nearly everyone has some hair loss with aging. The rate of hair growth also slows. Hair strands become smaller and have less pigment. So the thick, coarse hair of a young adult eventually becomes thin, fine, light-colored hair.
Hair will generally be at its best in the early 20s, says Burg, because “hair shafts are thick and cuticles are tight.” Women may see changes if they are stressed, extreme dieting or using contraception.
Your hair texture is constantly in flux, and the process starts a lot earlier than you may expect. “Hair aging is an ongoing, subtle process [that begins] from about the age of 16,” says Anabel Kingsley, brand president and consultant trichologist of Philip Kingsley.
Answer: No, hair does not thicken during puberty. As we age, the hair can feel courser and the growth of grey hairs add to this, but the actual hair density is unlikely to increase from puberty – unless you were previously unwell or deficient in a specific vitamin that then coincidentally improved around the same time.
Genetic factors appear to play a major role in determining hair texture—straight, wavy, or curly—and the thickness of individual strands of hair. Studies suggest that different genes influence hair texture and thickness in people of different ethnic backgrounds.
Hair follicles come in different shapes and sizes, affecting hair texture and width. Some people have wider follicles-and therefore, thicker hair strands-than other people. Genetics influence hair thickness, but other factors like hormones and age are important factors, too.
As you get older, your curls may drop, loosen, or even form new curl patterns due to hormonal changes, like menopause. Environmental factors such as gravity, climate, and pollution also play a part. The thinner and weaker your aging curly hair is, the less likely it is to actually curl.
For most women, this occurs sometime between the ages of 44 and 55. When your ovaries stop producing estrogen and progesterone—two hormones key to menstruating—this is when you go into menopause. Estrogen and progesterone also happen to be linked to your hair's health, including its growth.
The average ages pubic hair begins to grow in males and females are 12 and 11, respectively. However, in some females, pubic hair has been known to start growing as early as age 7.
As we age, our prolonged exposure to testosterone starts to play a visible role on other body hair as well. Just like it transforms the vellus hair on a young man's face into a thick beard, it also changes the nearly invisible hair that grows in places like our ears into thicker strands.
People with longer hair often notice changes in hair density and thickness between their roots and their ends. Indeed, it is a common problem for people who have medium to long hair.
Here's the hard truth: Little can be done to permanently change the diameter of individual hair strands. Thickening products can do wonders to temporarily plump hair strands, but when it comes down to it, fine hair is genetic and can't be changed.
Here's the truth: You can't change the size of your hair follicles. If you were born with fine hair, it's genetics, and no product will completely alter that. Of course, there are ways to maintain your hair health, add volume, and keep it from getting any thinner.
Vitamins B and D factor big in healthy hair. So do zinc, omega-3 fatty acids, and the B vitamin biotin. Your doctor can test you for deficiencies. Ask them whether you should take a multivitamin or supplement and how much.
It's all in your genes
The Hair Growth Cycle works in three stages but can vary a little from person to person therefore some people will appear to have a fuller head of hair depending on how long their hair grows before entering the shedding stage of the hair growth cycle.
2C type hair is extremely wavy but not coily. The S-shape bends in the hair start off at the roots. These waves are defined and thick. The bends are looser and wider than the tighter structure of curly hair.
Human hair comes with all sorts of colors, textures and shapes. Notably, African hair is more coiled and dry; Asian hair is straighter and thicker; and Caucasian hair is somewhere in between with around 45% having straight hair, 40% having wavy hair, and 15% having curly hair.
Curl pattern is genetically programmed just like eye color, height, and most other aspects of phenotype. Throughout our lives, however, we experience biological changes to our hair texture. By diameter, our hair tends to become gradually thicker into adulthood, thinning again in middle and old age.
Caucasians have the highest hair density among the ethnicities studied. Black people have the lowest. Asian people have hair density that falls somewhere in between.
Hair thickness is an “additive" trait. This means that if you inherited two copies of the “thick hair" version of the gene (one from each parent), you'll likely have even thicker hair strands than if you only inherited the "thick hair" version from one parent.
Men all have roughly the same amount of testosterone. Certain genes make your hair follicles more or less sensitive to the amount of testosterone in your body. Basically, an enzyme converts testosterone into a substance that shrinks hair follicles.