Incognitus
Well-Known Member
I perceive this (and lead hair theory) to be the basic life cycle of hair. Each strand is at various stages of the cycle. So it makes sense that there will be times when certain strands remain the same length, while other are catching up (thus increasing overall hair--not strand-- thickness).
1) Anagen: The hair shaft growth phase
The hair is “full of life”. There is constant rapid cell growth in the bulb. Hair grows on average at 1/2 an inch a month. Although the typical person’s hair is unlikely to grow more than one yard long. The duration of this phase determines length of hair shaft. This phase lasts between 2-7 years depending on gender and personal characteristics. For example if my anagen phase lasts for 5 years and I’m growing ½ inch a month then I should have 30 inches of hair. Diet, hormones, mechanical and chemical damage to my hair can affect how long I can grow my hair. During the anagen phase, hair grows as dead cells of keratin are pushed out through the scalp. The sebaceous glands produce an oily substance called sebum, which helps to condition and protect the hair. A healthy person has 85-90% of all hair is in this phase.
2) Catagen: recession phase
The hair is now between life and death as cells begin to die. At this time the dermal papilla, which nourishes all hair follicles and brings food and oxygen to the lower layers of epidermal cells, begins to separate from the follicle. The sebaceous glands produce less sebum and the hair stops growing. During this time a club hair is formed as part of the hair follicle attaches to the hair shaft. This prevents the hair from receiving any more nourishment via the blood supply. After 1-2 weeks, the hair begins the telogen phase.
3) Telogen: Resting and expelling phase
The hair is just sitting there until it gets pushed out the way and falls out. This phase lasts 5-6 weeks. Now the hair is “dead”. It just sits there still attached to the head but is not growing. The follicle does not produce keratin. Club hair is fully formed. After this old dead hair is done resting it falls out naturally. Then the cycle starts again back at anagen when a new hair is born. Some times this new hair is what kicks the old hair out.
1) Anagen: The hair shaft growth phase
The hair is “full of life”. There is constant rapid cell growth in the bulb. Hair grows on average at 1/2 an inch a month. Although the typical person’s hair is unlikely to grow more than one yard long. The duration of this phase determines length of hair shaft. This phase lasts between 2-7 years depending on gender and personal characteristics. For example if my anagen phase lasts for 5 years and I’m growing ½ inch a month then I should have 30 inches of hair. Diet, hormones, mechanical and chemical damage to my hair can affect how long I can grow my hair. During the anagen phase, hair grows as dead cells of keratin are pushed out through the scalp. The sebaceous glands produce an oily substance called sebum, which helps to condition and protect the hair. A healthy person has 85-90% of all hair is in this phase.
2) Catagen: recession phase
The hair is now between life and death as cells begin to die. At this time the dermal papilla, which nourishes all hair follicles and brings food and oxygen to the lower layers of epidermal cells, begins to separate from the follicle. The sebaceous glands produce less sebum and the hair stops growing. During this time a club hair is formed as part of the hair follicle attaches to the hair shaft. This prevents the hair from receiving any more nourishment via the blood supply. After 1-2 weeks, the hair begins the telogen phase.
3) Telogen: Resting and expelling phase
The hair is just sitting there until it gets pushed out the way and falls out. This phase lasts 5-6 weeks. Now the hair is “dead”. It just sits there still attached to the head but is not growing. The follicle does not produce keratin. Club hair is fully formed. After this old dead hair is done resting it falls out naturally. Then the cycle starts again back at anagen when a new hair is born. Some times this new hair is what kicks the old hair out.
Last edited:
