How Does My Body Hair Know When To Stop Growing?
There’s a good reason you don’t have long, flowing locks all over your body.
It always seems weird — but extremely fortunate — that our body hair just stops growing at a certain length. It means, for example, that even if we leave our pubes unattended for several months, we can reasonably expect them not to grow halfway down to our knees. But how come?
Every hair follicle on our bodies has a growth cycle that consists of three stages. There’s the anagen phase (when the hair grows); the catagen phase (when the hair stops growing and takes a rest); and the telogen phase (when the hair falls out). After this, it cycles back to the anagen phase.
“Different body hair has different times for each stage, hence the different lengths of hair,” explains dermatologist and trichologist David Kingsley. So despite the fact that it may appear to keep growing, scalp hair actually has a cycle that lasts about two to six years, growing about a half-inch per month. For our arms, legs, eyebrows and eyelashes, the growth phase only lasts about a month or so, then the hairs rest for a couple of weeks before falling out. The end result is that your body hair can only reach a certain length, and we all manage to avoid looking like untamed yaks.