Suddenly losing a lot of hair? Telogen effluvium, autumn shedding and when to worry
Quick answer
Losing 50 to 100 hairs a day is normal. When you suddenly start losing a lot more, spread evenly across the scalp and with no bald patches, the most likely cause is telogen effluvium: temporary shedding that shows up 2 to 3 months after a trigger (severe stress, fever, a crash diet, surgery, low iron or vitamin D, a change of season) and settles on its own within 3 to 6 months once the trigger is gone. In autumn there's also seasonal shedding that affects almost everyone: it's the hair your body held in the resting phase over the summer, all letting go at once. It isn't male pattern baldness and it won't make you bald. If it lasts more than 6 months, if bald patches appear or if you have other symptoms, see a dermatologist and get a blood test.
Shower. You run a hand through your hair and it comes away with hair in it. Lots of it. Or you check the bathroom sink in the morning and there's a rug in the plughole. Then another one on the pillow. You look at your profile picture from a year ago and can't tell whether it's the lighting or you're actually going bald.
Breathe. First: almost certainly not. Second: it's September, and what's happening to you is happening right now to half of Europe. We'll explain what telogen effluvium is, why autumn is peak shedding season, how long it lasts, how to tell whether it's this or your dad's hairline, and what to do in the meantime so you don't make it worse.
Where are you noticing it?
In the shower
One pass of the hand and out it comes in clumps.
On the pillow
You get up. Your hair stays in bed.
In the sink
The plughole looks like a rug.
On your clothes
The dark hoodie gives you away.
- How much hair is normal to lose a day?
- The hair cycle in 30 seconds
- What telogen effluvium is
- Why is my hair falling out? The usual triggers
- Why hair falls out more in autumn
- Telogen effluvium or male pattern baldness?
- What to do when you're losing a lot of hair (and what not to do)
- When to see a dermatologist
- FAQ
- Sources and evidence
How much hair is normal to lose a day?
You've got somewhere between 100,000 and 150,000 hairs on your head, and each one does its own thing. Losing 50 to 100 a day is normal: those are the hairs that have finished their cycle and are making room for new ones. You notice them more on the days you wash your hair (because they all come loose at once) and if your hair is long or dark, because they're easier to see. A guy with short blond hair loses just as many and never notices.
Losing hair isn't the problem. Losing more than grows back is.
The hair cycle in 30 seconds
- Anagen, the growth phase. Lasts 2 to 6 years. At any given moment, 85-90% of your hair is here.
- Catagen, the transition phase. Two or three weeks. The follicle shuts down.
- Telogen, the resting phase. About 3 months. The hair has stopped growing but stays put, waiting for the next one to push it out. That's 10-15% of your head.
Remember this: telogen = resting, and it lasts 3 months. It's the key to everything that follows.
What telogen effluvium is
Telogen effluvium happens when far more hairs than usual move into the resting phase at the same time. Because that phase lasts about 3 months, you don't see the shedding when the trigger happens: you see it three months later, when all those hairs that switched off together fall out… together.
That's why it's so hard to connect the dots. Your hair starts falling out in October and you don't link it to the flu you had in July, the break-up in June or the May diet to get beach-ready that took 8 kilos off. The trigger is always a few months back.
How to recognise it
- Shedding spread across the whole scalp, not at the temples or crown.
- Lots of hairs with a small white bulb at the root: that's the telogen bulb, and it's normal.
- No clearly bald areas.
- A fairly sudden start.
If you run a hand through dry hair and 3 or 4 hairs come away every time, that fits with telogen effluvium.
Why is my hair falling out? The usual triggers
Think about what happened to you 2 or 3 months ago. It's almost always on this list:
| Trigger | What happens | How long until it settles |
|---|---|---|
| Severe or ongoing stress | A break-up, losing your job, big exams, moving house, a bereavement. Cortisol pushes follicles into the resting phase. | Once the stress eases, 3-6 months. |
| High fever or infection | A nasty flu, COVID, anything that takes you to 39 °C. One of the most typical triggers. | 3-6 months; recovery is almost always complete. |
| Crash diet or rapid weight loss | Under 1,200 kcal, little protein, long fasts. Hair is the first thing your body stops feeding. | Once you're eating properly again, 3-6 months. |
| Surgery or anaesthesia | Your body prioritises healing; your hair waits its turn. | 3-6 months. |
| Low iron, vitamin D or zinc | Common in strict vegetarians, endurance athletes and people who eat badly. Shows up in a blood test (ferritin, 25-OH vitamin D). | Once the deficiency is corrected, 3-6 months. |
| Thyroid | Both an underactive and an overactive thyroid cause diffuse shedding. Blood test (TSH). | With treatment. |
| Medication | Oral retinoids (isotretinoin), beta blockers, blood thinners, some antidepressants. | Talk to whoever prescribed them; don't stop them on your own. |
| Change of season | Seasonal autumn shedding. It gets its own section. | A few weeks. |
Why hair falls out more in autumn
It's not a hairdresser's myth. A Swiss study that analysed 823 women over 6 years and a French one that followed a group of men for 8 to 14 years reached the same conclusion: the share of hairs in the resting (telogen) phase peaks in summer, between late summer and early autumn. And because the resting phase lasts a few months, the shedding arrives in September, October and November. The most widely accepted explanation is evolutionary: in summer the body holds more hair in the resting phase (as sun protection, the theory goes) and in autumn it lets go. We're mammals. We moult.
Add to that everything you put your hair through between June and August: sun, chlorine, salt water, more beers and fewer vegetables, worse sleep. Autumn isn't the cause: it's the bill.
- When it starts: between late August and September.
- How long it lasts: a few weeks. By November or December things should be back to normal.
- How noticeable it is: more shedding than usual at the peak, always spread out.
- What comes back: all of it. Seasonal shedding doesn't destroy follicles.
And yes, it happens to women too, and to guys with shampoo-advert hair. It's the only democratic kind of hair loss.
Telogen effluvium or male pattern baldness? How to tell
This is the question that really brought you here. The short answer: where it falls out, and how it progresses.
| Telogen effluvium | Androgenetic alopecia | |
|---|---|---|
| Where | All over the scalp, diffuse | Temples, crown, front hairline |
| How it starts | Suddenly, a lot, within weeks | Slowly, over years, with no dramatic shedding |
| The hair that falls out | Thick, normal, with a white bulb | Increasingly fine and short (miniaturised) |
| Bald patches | No | Yes, progressively |
| How it progresses | Settles within 3-6 months | Keeps progressing if untreated |
| Genetics | Don't matter | Matter, and not just your maternal grandfather's |
| Treatment | Remove the trigger; the rest is care | Minoxidil, finasteride and, as support, cosmetic hair care |
One important point: the two can happen together. Telogen effluvium in someone with early male pattern baldness exposes what was already there, and once the shedding settles, density ends up lower than before. If it runs in your family and you're now shedding, it's a good moment to start looking after your hair properly, not to wait and see.
What to do when you're losing a lot of hair (and what not to do)
Telogen effluvium clears up once you remove the cause and wait. But while you're waiting, some things help and some make it worse.
- Find the trigger. The one from 2-3 months ago. If it's stress, diet or sleep, that's what you need to fix; your hair is just sending you the warning.
- Don't declare war on your hair. Washing it less doesn't reduce shedding (hairs in the telogen phase will fall out anyway, just all at once). Washing it with a harsh shampoo, on the other hand, does make your scalp worse. Wash it every day if you need to, with something gentle.
- Stop counting. Seriously. Counting hairs in the shower is the fastest way to turn telogen effluvium into an anxiety problem, which is itself a trigger. A vicious circle of the worst kind.
- Eat. Enough protein, iron, zinc and vitamin D. If you've been on a crash diet, now's the time to stop. If you suspect a deficiency, blood test first, supplement second.
- Give your scalp a boost. Not to "stop" the shedding (you can't stop it, it passes), but so the recovery phase goes better: circulation, active follicles, a clean scalp with no inflammation.
This is where Siwon comes in, with exactly the right expectations. Hairicane is a strengthening shampoo that cleanses with plant-based surfactants and contains our botanical complex at 3%, with red onion extract, ginseng, zinc, niacinamide and biotin. Its job is to look after your scalp, not punish it. It's the shampoo you'd use in exactly the same way during telogen effluvium, with minoxidil, or with nothing at all. If you want to go a step further, Follicool then applies the same botanical complex at 10%, together with 5% Capixyl™ and caffeine, as a daily serum on a dry scalp.
Neither of them "cures" telogen effluvium, because it can't be cured with cosmetics. What they do is make sure that when the new hair starts coming through, the ground is in the right condition.
€22.99
Hairicane
Strengthening and redensifying shampoo. Cleans without punishing a scalp that's already having a rough time.
- Plant-based surfactants: cleans without stripping
- Botanical complex at 3%
- Red onion, ginseng, zinc, niacinamide and biotin
€45.99
Follicool
Intensive scalp serum in a spray. On a dry scalp, no rinsing.
- Botanical complex at 10%
- Capixyl™ at 5%: the concentration used in its study*
- Caffeine, green tea and saw palmetto
Free shipping from €59. *Ingredient study carried out by the ingredient's manufacturer, under the conditions of that study. Hairicane and Follicool are cosmetics: they are not medicines, and they don't prevent or treat any disease, including telogen effluvium or alopecia.
On supplements: if the trigger was a diet or you suspect you're low on zinc, biotin or vitamin D, a supplement like Growzilla, which contains biotin, zinc and vitamin D3, can help you cover those nutrients (biotin and zinc contribute to the maintenance of normal hair). But blood test first. A supplement for a deficiency you don't have is money down the plughole, right along with your hair.
When to see a dermatologist
- If the shedding lasts more than 6 months (chronic telogen effluvium).
- If there are bald patches or clearly thinned areas, especially round ones (that could be alopecia areata, which is a different thing entirely).
- If you also have extreme tiredness, weight changes, palpitations or very dry skin: it could be your thyroid or a significant deficiency.
- If your scalp itches, burns or crusts, or flakes heavily: the problem may be your scalp, not your hair.
- If male pattern baldness clearly runs in your family and you want to know where you stand before deciding on treatment.
Seeing a dermatologist about hair loss isn't being soft. It's the difference between sorting it out in 3 months and fretting about it for a year.
FAQ about sudden hair loss
How long does telogen effluvium last?
Between 3 and 6 months from when the shedding starts, as long as the trigger has gone. Seasonal autumn shedding lasts a few weeks. If it goes on for more than 6 months, it's considered chronic and should be investigated.
Does hair grow back after telogen effluvium?
Yes. Telogen effluvium doesn't damage the follicle, it just brings the shedding forward. New hair takes a while to show because it grows roughly a centimetre a month, so density comes back gradually over the following months.
Why does hair fall out more in autumn?
Because in summer a larger share of hairs moves into the resting phase, and in autumn they let go. This seasonal shedding has been observed in follow-up studies lasting several years, in both men and women. It lasts a few weeks and the hair recovers.
Is it normal for hair to fall out in clumps?
It's typical of telogen effluvium, especially when washing or combing. What isn't normal is for it to last more than 6 months, for bald patches to appear or for it to come with other symptoms.
Can stress make your hair fall out?
Yes, intense or prolonged stress is one of the most common triggers of telogen effluvium. The shedding appears 2-3 months after the peak of stress, which is why the two are so hard to connect.
Does washing your hair less reduce shedding?
No. Hairs in the resting phase will fall out anyway; if you don't wash, you just see them all at once on the day you do. Wash your hair when you need to, with a gentle shampoo.
Does minoxidil help with telogen effluvium?
It isn't indicated for that. Telogen effluvium resolves on its own once the cause is removed. Minoxidil is for androgenetic alopecia. If you have both, get a dermatologist to assess you.
What blood tests should I get for hair loss?
The usual ones: full blood count, ferritin, vitamin D (25-OH), zinc and TSH. Your GP can order them; they rule out deficiencies and thyroid problems, the most common triggers you can't see with the naked eye.
Sources and evidence
The studies this article is based on, so you can read them yourself:
- Kunz M., Seifert B., Trüeb R.M. Seasonality of hair shedding in healthy women complaining of hair loss. Dermatology (2009).
- Courtois M. et al. Periodicity in the growth and shedding of hair. Br J Dermatol (1996).
- Telogen Effluvium — a review of the science and current obstacles (2021).
- Kaiser M. et al. Treatment of Androgenetic Alopecia: Current Guidance and Unmet Needs (2023).
- Regulation (EU) 432/2012 — authorised health claims (biotin, zinc).
Autumn passes
Most telogen effluvium passes too. What doesn't pass on its own is the habit of treating your scalp badly. If you only change one thing this month, make it your shampoo.
See HairicaneNote: this article is for general information only and does not replace an assessment by a healthcare professional. Hairicane and Follicool are cosmetic products, not medicines, and they don't prevent or treat any disease. Food supplements should not be used as a substitute for a varied, balanced diet. If your hair loss lasts more than 6 months, appears in patches or comes with other symptoms, see a dermatologist.