Incredible How Fast Does Human Hair Grow Ideas. Web here's how factors like your age, ethnicity and even the time of year influence your hair's growth. Web it’s the longest phase, lasting about 3 to 5 years for the hairs on your head, though for some people a single hair could continue growing for 7 or more years.

At the end of anagen phase, the hair enters the catagen phase. The full strand of hair develops from this group of hardened hair cells. Web the growth phase, or anagen, lasts an average of 3 to 5 years, and hair grows around half an inch per month [during this time].