Hair growth and shedding follow a precise biological rhythm called the "Hair Cycle," composed of three successive phases: growth, transition, and rest/shedding. Understanding this cycle helps explain why hair grows, rests, falls out, and then regrows.
This mechanism, well documented by the Swiss dermatological society and the international scientific community , plays an essential role in the density, thickness and overall quality of the hair.
In Geneva, many patients consult a specialist to better understand hair regrowth, the duration of hair growth phases, and normal variations from person to person. This article clearly explains how this cycle works, when it can become disrupted, and the signs to watch for.
Each hair develops independently, preventing a massive, simultaneous shedding. A complete cycle lasts on average 2 to 7 years, depending on genetics, age, sex, and hormones ( source ). The hair follicle naturally alternates between 3 key phases:
On a daily basis, approximately 90% of hairs are in the growth phase, and only 10 to 15% are in the resting phase. This distribution ensures stable hair despite constant renewal.
Good to know: to understand how certain factors such as stress or lack of sleep can influence these cycles and amplify hair loss, you can consult our article dedicated to this subject.
The anagen phase is the longest – approximately 2 to 7 years.
It determines the maximum length your hair can reach. During this phase, the hair follicle renews itself rapidly, continuously producing keratin. This is why 80 to 90% of your hair is permanently located in this phase.
The duration of the anagen phase depends on factors such as genetics, ethnic heritage, hormonal status, or the natural aging of the follicle.
Note well: a shorter anagen cycle explains why some hairs remain short despite all hair care.
The catagen phase lasts only 2 to 3 weeks.
The follicle stops producing keratin, shrinks slightly, and then prepares for rest. Less than 5% of your hair is in this stage. As you might have guessed, this phase marks the end of active growth.
The telogen phase, the final stage of the hair cycle, lasts on average 2 to 4 months.
The hair ceases all activity, remains attached but inactive, and is then gradually shed as a new hair begins to grow. This mechanism explains the normal shedding of between 50 and 100 hairs per day. A temporary increase in the number of hairs in the telogen phase can cause more pronounced shedding (effluvium), but without permanent thinning if the follicle remains healthy.
Good to know: telogen effluvium is when hair falls out in greater quantities than usual after an episode of stress, pregnancy, nutritional deficiency or various external aggressions, with a phenomenon that generally remains transient.
Hair grows on average 1 to 1.3 cm per month, but this rate can vary depending on the area of the scalp. Growth is often slightly faster at the crown and generally slower at the temples, which explains some differences in natural density.
The speed also depends on the duration of the anagen phase, age, hormones, natural hair diameter, and general health.
To assess the quality of hair regrowth or the activity of the hair follicle, the Croix d'Or Hair Clinic performs precise examinations: diagnosis, scalp analysis, and densitometry. If you have any questions, please schedule an appointment with our hair surgeon, Dr. Meyer .
A hair cycle can become abnormal when:
In these cases, it is recommended to consult a doctor to distinguish between a menstrual cycle irregularity, a deficiency, a hormonal disorder, or early-stage alopecia .
Our team uses several tools to understand the behavior of your hair follicles: anagen/telogen analysis, scalp inspection, measurement of follicle diameter and density, and research into associated factors.
Following this diagnosis, our hair specialist will guide you towards the solutions best suited to your situation. Feel free to ask us for advice or take an online diagnosis on our website.
The hair life cycle follows a complex but perfectly natural rhythm: growth, transition, rest, and then renewal. Understanding this mechanism helps to recognize what is normal and what is not. If you notice unusual hair loss, slowed regrowth, or thinning areas, a professional opinion can make all the difference.
Make an appointment today for personalized and high-quality aesthetic care. Our team of experts is here to offer you innovative treatments tailored to your needs.
Please select all the means by which you would like to receive information from the Clinique de la Croix d'Or:
You can unsubscribe at any time by clicking the link in the footer of our emails. For more information about our privacy practices, please review the privacy policy on our website.
We use Mailchimp as our marketing platform. By clicking below to subscribe, you acknowledge that your information will be transferred to Mailchimp for processing. Learn more about Mailchimp's privacy practices