Telogen effluvium in London: why you're shedding, what actually works, and how long recovery really takes

Telogen effluvium is the London commuter's hair diagnosis. It surges through the clinic diary every February (winter illness), every October (post-summer crash diet and holiday burnout) and every year 12–14 weeks after the last major viral wave. It is common, benign, and — for most people — terrifying in the moment because nobody has explained the physiology.

This is that explanation. It is written for the patient who has been told by a friend / hairdresser / GP that they are 'probably stressed' and to 'stop worrying'. Both of those statements can be true and still miss the point. The point is: your follicles are in the wrong phase of the cycle, we know why, and the recovery is real but slow.

What telogen effluvium actually is

The hair cycle has three phases: anagen (growth, 2–6 years), catagen (transition, 2 weeks) and telogen (rest, 3 months, at the end of which the hair sheds and a new anagen hair pushes through). At any moment a healthy scalp has around 85% of follicles in anagen and 10–15% in telogen.

In TE, a systemic stressor — illness, surgery, childbirth, sudden weight loss, iron collapse, thyroid change, a new medication — shifts a large cohort of anagen follicles synchronously into telogen. Nothing sheds immediately, because telogen lasts three months. Then, 8–14 weeks later, you spill 200–400 hairs a day for weeks, and the shower drain becomes a crisis.

The 10 most common London triggers

Any one of these can trigger TE. Two or three stacked (post-viral + iron drop + calorie restriction is the classic winter triad) reliably will.

• Viral illness — flu, COVID, glandular fever, any high-fever week.
• Surgery under general anaesthetic — the shed usually arrives 10–14 weeks post-op.
• Postpartum — the sharpest and most predictable trigger, typically 3–6 months after delivery.
• Crash dieting or rapid weight loss — anything more than 5–7 kg lost in 6 weeks is high-risk.
• Iron / ferritin collapse — often from heavy menstrual bleeding or plant-based diet without supplementation.
• Thyroid change — both hypo- and hyperthyroid trigger it, as does starting or adjusting levothyroxine.
• Medication change — SSRIs, beta blockers, statins, hormonal contraception starts/stops, retinoids.
• Emotional shock — bereavement, breakup, redundancy, a genuinely bad three months.
• Severe caloric restriction (protein specifically) — ketogenic and low-protein regimes are notable culprits.
• Vitamin D deficiency — endemic in London latitudes, especially October–April.

How a London trichologist confirms the diagnosis

A proper TE workup is roughly 60 minutes and £120–£250 privately, or a 15-minute GP appointment plus blood tests on the NHS with a 6–18 week wait to see anyone with real scalp expertise.

The exam has three parts. First, a pull test — 60 hairs grasped at 3 scalp regions, gentle traction, more than 6 hairs shedding suggests active TE. Second, trichoscopy — a dermatoscope camera at 20–70x looking for the twin questions: is there miniaturisation (which would mean pattern loss under the TE), and are follicular openings preserved (which rules out scarring alopecia). Third, bloods.

The blood panel that actually matters

Half of TE workups in London are done with the wrong panel. The right one is not exotic — it just needs to be complete, and interpreted with hair-specific thresholds, not general population ranges.

• Full blood count — screening for anaemia and infection.
• Ferritin — aim >70 μg/L for hair, not the lab's default 'normal >15'.
• TSH, free T4 and thyroid antibodies — subclinical thyroid disease is a very common miss.
• Vitamin D (25-OH) — target >75 nmol/L for hair; London winters routinely drop patients below 50.
• Vitamin B12 and folate — especially in vegetarian, vegan or bariatric patients.
• Zinc — worth adding when the diet history is restrictive.
• In female patients with menstrual irregularities: LH, FSH, testosterone, SHBG, DHEAS, prolactin to screen for PCOS.
• In peri- and post-menopausal patients: symptom-driven hormone panel, not routine.

Recovery: what to actually do, in order

Recovery from acute TE is largely spontaneous — the follicles will re-enter anagen on their own, on their own timeline. Your job is to remove the ongoing trigger, correct any deficiency, and (optionally) accelerate the return with minoxidil.

• Weeks 0–4: correct deficiency. Iron with vitamin C if ferritin is low; vitamin D3 2,000–4,000 IU daily; treat thyroid if abnormal; add adequate protein (>1.2 g/kg/day).
• Weeks 0–4: eliminate the ongoing trigger where possible — this is the single highest-yield step.
• Weeks 4–12: introduce topical minoxidil 5% (men) or 2–5% (women) if pattern loss is also present, or if you want to shorten the shedding phase. Expect an initial shed at week 2–6 of minoxidil — this is expected.
• Weeks 4–12: gentle scalp care — nothing aggressive, no traction hairstyles, warm rather than hot washes, sulphate-free shampoo 2–3x weekly.
• Months 3–6: expect visible short new hairs at the hairline and parting — 1–3 cm regrowth is normal by month 6.
• Months 6–12: cosmetic density returns. Trichoscopy at month 6 to confirm the story matches the scalp — if not, revisit the differential.
• Months 12+: if still shedding at 6+ months, this is now chronic TE — different workup, dermatology referral appropriate.

What to skip

Biotin at 5,000–10,000 mcg is the great London supplement waste of the last decade — it is only useful in true biotin deficiency, which is vanishingly rare, and it distorts thyroid and cardiac blood tests. Collagen peptides help skin more than hair. 'Hair vitamins' at Boots are almost always a multivitamin with extra biotin and a marketing budget.

Aggressive PRP courses during acute TE are usually premature — waiting 3–6 months for the natural cycle to reset first tells you whether you needed PRP at all. Transplants during an active shed are strictly contraindicated: you cannot assess the donor pattern.

When it isn't telogen effluvium

TE is diffuse and reversible. Pattern loss is patterned (parting, crown, temples) and progressive. Scarring alopecia (frontal fibrosing alopecia, lichen planopilaris, CCCA) shows loss of follicular openings on trichoscopy and is not reversible — early diagnosis is critical because active disease can be halted but lost hair cannot return.

If your shed has lasted longer than six months, is asymmetric, is accompanied by burning / itching / redness / smooth patches, or if the hairline is receding rather than diffusely thinning, this is not simple TE. Insist on a scalp exam with trichoscopy.