Telogen effluvium
back to main page
Telogen effluvium is one of the most common forms of non-scarring hair loss, associated with a disruption of the hair growth cycle. It involves the premature transition of a large number of hair follicles from the growth phase (anagen) to the resting phase (telogen), resulting in increased hair loss a few weeks or months after the triggering factor. The condition can be acute or chronic and affects both women and men. Telogen effluvium very often occurs after severe physical or psychological stress, illnesses, childbirth, rapid weight loss, nutritional deficiencies, and hormonal disorders. In most cases, the process is reversible, provided the cause of the disorder is eliminated.
Telogen effluvium - what it is
The hair life cycle includes three basic phases:
- anagen – the active hair growth phase,
- catagen – the transitional phase,
- telogen – the resting phase ending with hair shedding.
Under normal conditions, about 85–90% of hair is in the anagen phase, while only 10–15% is in telogen. In telogen effluvium, these proportions are disrupted. A significant number of hair follicles simultaneously enter the resting phase, which leads to increased, diffuse hair loss across the entire scalp.
A characteristic feature of telogen effluvium is the absence of permanent damage to the hair follicles. This means that the process does not lead to scarring of the skin or irreversible atrophy of the follicles. Hair usually regrows after the body's condition stabilizes.
Telogen effluvium can occur in two forms:
Type | Characteristics |
|---|---|
Acute telogen effluvium | lasts less than 6 months |
Chronic telogen effluvium | persists for more than 6 months |
The chronic form is more commonly associated with hormonal disorders, chronic stress, nutritional deficiencies, or systemic diseases.
Telogen effluvium - how it progresses
Telogen effluvium usually develops with a delay relative to the triggering factor. Between the onset of the trigger and the appearance of increased hair loss, usually about 2–4 months pass. This results from the biology of the hair cycle – the hair remains in the follicle for some time after transitioning to the telogen phase.
Patients most commonly observe:
- an increased amount of hair during washing,
- hair left on the brush and pillow,
- decreased hair volume,
- diffuse hair thinning without distinct patches of hair loss.
Unlike androgenetic alopecia, there is usually no gradual receding of the hairline or miniaturization of follicles in specific areas of the scalp. The process is more uniform.
Diagnostics include, among other things:
- medical history,
- trichological evaluation of the scalp,
- hair pull test,
- trichoscopy,
- laboratory tests assessing deficiencies and hormonal disorders.
Identifying the causative factor is crucial, as symptomatic treatment alone without eliminating the cause usually yields limited results.
Telogen effluvium - causes
Telogen effluvium is a reaction of hair follicles to the stress on the body. The most common causes include:
Metabolic and nutritional factors
- iron deficiency,
- ferritin deficiency,
- zinc deficiency,
- protein deficiency,
- B-group vitamin deficiencies,
- restrictive weight-loss diets.
Hormonal disorders
- thyroid diseases,
- postpartum period,
- discontinuation of hormonal contraception,
- polycystic ovary syndrome,
- menopause.
Diseases and burdens on the body
- infections with high fever,
- COVID-19,
- surgical procedures,
- chronic diseases,
- severe psychological stress.
Medicines
- retinoids,
- anticoagulants,
- some antidepressants,
- drugs used in obesity therapy,
- chemotherapy.
An increasing clinical significance is also observed in the case of rapid weight loss associated with GLP-1 receptor agonist therapies, such as semaglutide or tirzepatide. The drug itself is not always the direct cause of hair loss – a key role is often played by the rapid rate of body fat reduction and nutritional deficiencies.
Telogen effluvium and weight loss - the connection
Rapid weight loss is one of the most common factors triggering telogen effluvium. The body treats rapid weight loss as a state of metabolic stress and limits processes that are not essential for survival, including intensive hair growth.
The greatest risk occurs during:
- very low-calorie diets,
- fasting,
- elimination diets,
- rapid weight loss after bariatric surgery,
- intensive weight reduction after GLP-1 medications.
Of key importance are:
- protein deficiency,
- iron deficiency,
- reduced calorie intake,
- micronutrient deficiencies,
- hormonal imbalances associated with the loss of adipose tissue.
Adipose tissue acts as an active endocrine organ. It produces, among others, leptin, estrogens, and cytokines that affect metabolism and the functioning of hair follicles. Its rapid reduction can disrupt the body's hormonal homeostasis.
In clinical practice, telogen effluvium after weight loss very frequently co-occurs with:
- skin laxity,
- loss of facial volume,
- deterioration of skin quality,
- weakened nails.
To limit the risk, gradual weight loss and an appropriately balanced diet, including the intake of protein, iron, and micronutrients, are recommended.
Telogen effluvium - is it reversible
In the vast majority of cases, telogen effluvium is reversible. After removing the triggering factor, hair follicles gradually return to their normal growth cycle.
The first signs of hair regrowth usually appear after:
- 3–6 months from the elimination of the cause,
- correcting deficiencies,
- hormonal stabilization,
- improving the metabolic state of the body.
Complete restoration of hair density may, however, require up to 12–18 months, especially after severe deficiencies or very significant weight loss.
Therapeutic management includes:
- causal treatment,
- correcting deficiencies,
- improving protein intake,
- trichological therapy,
- scalp stimulation.
In aesthetic and regenerative medicine, the following are used, among others:
- scalp mesotherapy,
- platelet-rich plasma,
- peptide therapy,
- biostimulating treatments,
- therapies supporting scalp microcirculation.
However, it should be emphasized that supportive treatments do not replace systemic diagnostics. Persistent hair loss requires medical evaluation and the exclusion of metabolic, hormonal, and autoimmune diseases.
