There are many influence factors that can affect the hair cycle such as age, heredity, hormones, medication, nutrition and even stress. Nevertheless, we all share the same hair cycle, broken down into four phases: anagen, catagen, telogen and exogen.
Anagen
This is the hair cycle’s growth phase and it is influenced by the condition of the dermal papilla, which is voluminous and made up of a vascular core. The hair being rich in melanin and hydration, this phase is the target of electroepilation and photoepilation treatments.
The length of the hair varies depending on the body region, age, sex and the individual person. With an anagen phase of 2 to 6 years, hairs can reach a length of 1.28 meters (approximately 4 feet). The anagen phase varies from 1 to 12 months for certain regions of the body, which means hair in these areas can grow from 1 to 6 cm (approximately 0.4 to 2.3 inches).
| Area | Hair | Eyebrows | Upper lip | Chin | Underarms | Arms | Bikini | Legs |
| Duration of the anagen phase | 2-6 years | 1-2 months | 4 months | 1 year | 4 months | 2-4 months | 2-4 months | 4 months |
Catagen
It is a transitional phase during which hairs stop growing, but remain attached to the dermal papilla. At this point, melanin is also no longer produced in the germinative zone. The catagen phase is the shortest and generally doesn’t last more than two or three weeks.
Telogen
This resting phase, during which cells are inactive, involves no growth of the hair shaft. Papilla atrophy occurs and the hair is ready to fall and be replaced by a new anagen hair, after the beginning of the next growth cycle. Moreover, the telogen hair being less pigmented and having a white bulb, photoepilation results are not satisfying in this phase.
About 50 to 100 telogen hairs are normally shed each day, accounting for the hairs you see in the shower and when styling your hair.
Exogen
This last phase represents the hair expulsion process. During a photoepilation treatment, the complete expulsion can take between 6 to 21 days. Once the hair has fallen, its bulb is no longer visible.
It is important to remember that the hair phase greatly influences the efficiency of hair removal. This is in fact why it is paramount to respect a strict appointment calendar: assiduity will ensure the best results!