What is the Hair Growth Cycle?
Hair has a life cycle and hair growth takes place over the course of three stages, namely, the Anagen Phase (the growth phase), Catagen Phase (the transition phase), and the Telogen Phase (the resting phase).
Anagen Phase (Growth Phase)
The Anagen phase is the first and also the longest growth phase of your hair life cycle and lasts between 2-5 years. Around 85-95% of hairs on your head will be in this stage at any given point in time. This is the growth phase and hairs grow at an approximate rate of around 1cm per month.
The length of hair relates to the length of time in the Anagen phase, and the hair growth cycle duration varies for other areas of the body. For example, the reason why the length of hair on the head is far greater than the length of hair on the eyebrows is because the eyebrows are only in the Anagen phase for around 30 to 45 days.
Catagen Phase (Transition Phase)
The Catagen phase is known as the transition phase because this is the period of transition between the Anagen (growth phase) and the Telogen (resting phase).
The transition period takes place over a time span of around 2-3 weeks. Less than one percent of hairs on your head will be in this stage at any given point.
Telogen Phase (Resting Phase)
The Telogen phase is the resting phase of the growth cycle. Upon completion of this stage, hairs will start to enter the Anagen growth phase again. Around 10-15% of the hair on your scalp is in the Telogen phase at any given time.
This is typically the hair shedding period. You can expect around 25 to 100 hairs to shed every day during this phase. The hair follicles are resting and do not produce any new hair. Two or three months later the hair follicles become active again and new hair starts to grow, taking place during the Anagen phase and hence the life cycle has completed its loop.