If you do not cut your hair then you can grow it quite long, but there is an upper limit to the maximum length that you can grow your scalp hair.
There are various papers that examine the time duration for scalp hair follicles are actively producing a hair fiber. The most frequently quoted time period is 1000 days (2-6 YEARS), but this figure is a rough approximation. The time duration of anagen growth, plus knowing what length of hair fiber a scalp hair follicle can produce per day, will enable a calculation of the average maximum length that scalp hair can grow to. Research on humans suggests that active hair fiber growth production from scalp hair follicles may last from 500 to 1800 days. The scalp hair fiber growth rate is between 0.3 to 0.4 mm a day. For the most part, the studies were done with male volunteers, but a few other studies indicate similar results for women too.
If you put it all together in a calculation, the research would suggest that the maximum length scalp hair can grow to, is between 20 and 60 centimeters. However, from the picture below you can see that some people are able to grow their hair much longer. The upper limit to scalp hair length is determined by our genes. Some people have genes for short hair, others grow hair much longer.
The hormones called androgens are important control factors in hair growth and in inherited male and female patterns of hair loss. The androgen hormone testosterone and its metabolite dihydrotestosterone (DHT) are the key control factors:
Testosterone is a key control factor in the growth of beard, underarm and pubic hair.
Scalp hair loss is associated with presence of DHT in male and female pattern hair loss. DHT plus the presence and activity of hair loss gene(s) are the key factors underlying male and female pattern hair loss.
The androgens mediate their effect by binding to the androgen receptors present in the follicle. The testosterone is converted to DHT by the action of the enzyme 5-Alpha reductase. The DHT then binds to the receptor and initiates its action.
The hormones called androgens are important control factors in hair growth and in inherited male and female patterns of hair loss. The androgen hormone testosterone and its metabolite dihydrotestosterone (DHT) are the key control factors:
Testosterone is a key control factor in the growth of beard, underarm and pubic hair.
Scalp hair loss is associated with presence of DHT in male and female pattern hair loss. DHT plus the presence and activity of hair loss gene(s) are the key factors underlying male and female pattern hair loss.
The androgens mediate their effect by binding to the androgen receptors present in the follicle. The testosterone is converted to DHT by the action of the enzyme 5-Alpha reductase. The DHT then binds to the receptor and initiates its action.