Telogen Effluvium: Why Your Hair Is Falling Out in Clumps (and How to Stop It)
What is telogen effluvium?
Telogen effluvium is a form of diffuse hair shedding in which a physiological or emotional shock pushes a large percentage of hair follicles into the resting (telogen) phase simultaneously. Approximately 2 to 3 months later, these follicles shed their hair, resulting in sudden, dramatic thinning that affects the entire scalp. It is the second most common cause of hair loss after androgenetic alopecia and affects both men and women of all ages.
Unlike pattern hair loss (which follows a predictable progression at the temples and crown), telogen effluvium causes diffuse shedding across the whole scalp. Patients typically notice large amounts of hair in the shower, on the pillow, and in the brush, and may feel that their ponytail has lost half its volume or that their part line has widened significantly.
The reassuring reality: acute telogen effluvium is temporary and self-resolving in most cases once the trigger is addressed. However, when shedding persists, unmasks genetic thinning, or significantly affects quality of life, treatment can accelerate recovery.
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What triggers telogen effluvium?
The trigger occurs 2 to 3 months before the shedding begins. This delay is why many patients struggle to connect their hair loss with the cause.
Physical illness or high fever. Any significant illness including COVID-19, influenza, pneumonia, or severe infection can trigger telogen effluvium. Post-COVID hair shedding became one of the most widely recognised triggers during 2020 to 2023 and continues to be reported.
Major surgery or anaesthesia. The physical stress of surgery, combined with anaesthesia and post-operative recovery, frequently triggers shedding.
Childbirth. Postpartum telogen effluvium affects up to 50% of new mothers, driven by the rapid oestrogen withdrawal following delivery.
Severe emotional stress. Bereavement, relationship breakdown, job loss, financial crisis, or prolonged anxiety can trigger the cortisol-mediated stress response that disrupts the hair growth cycle.
Crash dieting or rapid weight loss. Losing more than 10kg over a short period frequently triggers shedding. Hair is a non-essential tissue that the body deprioritises when caloric intake drops dramatically.
Medication changes. Starting or stopping hormonal contraception, beta-blockers, anticoagulants (blood thinners), retinoids (acne medication), and certain antidepressants can all trigger telogen effluvium.
Thyroid dysfunction. Both hypothyroidism and hyperthyroidism disrupt the hair growth cycle and can cause persistent shedding until thyroid levels are stabilised.
Iron deficiency. Low ferritin (below 30 ng/mL) is one of the most common and most treatable triggers, particularly in women.
The recovery timeline
Months 1 to 3 after trigger: No visible hair loss yet. The internal shift has occurred but the resting phase takes 2 to 3 months before shedding begins.
Months 3 to 6 after trigger: Peak shedding. The most alarming period. Large volumes of hair fall daily.
Months 6 to 9: Shedding begins to slow. New growth (short baby hairs) may become visible at the hairline and part.
Months 9 to 12: Progressive recovery. Density gradually returns toward pre-trigger levels.
Beyond 12 months: If shedding persists, the condition may have become chronic telogen effluvium (trigger still present) or the episode has unmasked underlying androgenetic alopecia. Medical assessment is essential at this point.
Treatment approach
Step 1: Identify and address the trigger
This is the most important step. If the trigger is an ongoing condition (iron deficiency, thyroid dysfunction, chronic stress, nutritional inadequacy), the shedding will not resolve until the trigger is addressed. Blood work (ferritin, thyroid function, vitamin D, B12, zinc) is essential.
Step 2: Nutritional support
Correct any identified deficiencies. Iron supplementation for low ferritin. Vitamin D supplementation (1,000 to 4,000 IU daily). Adequate protein intake (at least 1g per kilogram of body weight). Medical-grade supplements such as Viviscal Professional to provide comprehensive follicular nutrition.
Step 3: PRP therapy (for persistent or severe cases)
PRP accelerates telogen effluvium recovery by delivering concentrated growth factors that stimulate follicles to re-enter the active growth phase more quickly. PRP is particularly indicated when shedding persists beyond 6 months, when the episode has revealed underlying genetic thinning requiring ongoing treatment, when the volume of loss is significantly affecting confidence and quality of life, or when patients want to proactively accelerate recovery rather than waiting.
PRP is safe and compatible with all other telogen effluvium treatments. At The London PRP Clinic: from £545 per session, 87% success rate.
Step 4: Monitor and reassess
Standardised photography at regular intervals objectively tracks recovery. If shedding resolves completely, no further treatment may be needed. If underlying genetic thinning is revealed, a long-term maintenance plan (PRP plus pharmaceutical treatment where appropriate) is recommended.
When telogen effluvium reveals something else
In approximately 20 to 30% of patients, the telogen effluvium episode unmasks underlying androgenetic alopecia that was previously unnoticeable. The hormonal shift or nutritional stress that triggered the acute shedding also accelerated the genetic miniaturisation that had been slowly progressing in the background.
These patients recover from the acute shedding but find that their hair does not return to its pre-trigger fullness. The thinning that remains is genetic pattern loss requiring ongoing management with combination therapy (finasteride for men, minoxidil, PRP).
This is another reason why medical assessment is valuable. Our doctors at The London PRP Clinic can distinguish between pure telogen effluvium (which will resolve fully) and telogen effluvium overlaying genetic thinning (which requires ongoing treatment) through clinical examination, hair pull testing, and scalp assessment.
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The London PRP Clinic by The Wellness
Our GMC-registered doctors provide comprehensive telogen effluvium assessment including trigger identification, blood work guidance, treatment planning, and ongoing monitoring.
PRP from £545. ExoRevive from £445. 87% success rate. 187+ five-star reviews. Marylebone and Canary Wharf.Free consultation.
Book your assessment > WhatsApp | Email: team@thewellnesslondon.com | Call: +44 20 3951 3429
Medical Disclaimer: Telogen effluvium requires medical assessment to identify the trigger and rule out other conditions. All consultations at The London PRP Clinic conducted by GMC-registered doctors. Last reviewed March 2026.