Autumn hair shedding: is seasonal hair loss real?

Autumn hair shedding: is seasonal hair loss real?

Quick answer: Seasonal hair loss looks real, but it is modest and the research is small. A UK study of 14 men found shedding peaked around August and September, and a Swiss study of 823 women found the most resting (telogen) hairs in summer. A bit more hair in the brush in early autumn is usually normal. Shedding that lasts more than a few months, or comes with patches or a sore scalp, is worth checking.

This post is for anyone in Belfast or elsewhere in Northern Ireland who has noticed more hair in the plughole this October or November and wants to know whether to worry. We'll go through what the studies actually measured, what they didn't, and the signs that point to something other than the season.

What "seasonal hair loss" means

Every hair on your head goes through a growing phase (anagen) and a resting phase (telogen). At the end of the resting phase, the hair falls out and a new one usually starts to grow in the same follicle.

Seasonal hair loss is the idea that more of your follicles move into the resting phase at certain times of year, so more hairs fall out together a little later. It's a normal cycle, not damage to the follicle. The NHS hair loss page says we can lose between 50 and 100 hairs a day, often without noticing. If you want to know what that looks like in real life, our post on how much hair loss is normal goes into it.

What the research found

There are only a handful of studies on this, and each one measured something slightly different. Here's what three of them did.

A small UK study that counted shed hairs

In 1991, Randall and Ebling measured hair growth every 28 days for 18 months in 14 healthy men in Sheffield. They found the proportion of scalp follicles in the growing phase peaked at over 90% in March and dropped to its lowest point in September.

The number of shed hairs peaked around August and September. At that point the men lost about 60 hairs a day on average, more than double the figure from the winter before.

This is the study most often behind the "autumn shedding" claim, and it's the closest to home: Sheffield is in the north of England, so the daylight pattern is not far off ours. But it was 14 men, all with indoor jobs. It tells us nothing directly about women, and 14 people is a very small group.

A larger Swiss study in women

In 2009, Kunz, Seifert and Trüeb looked back over six years of records from a dermatology department in Zürich. The women in the study had come in worried about hair loss. After removing anyone with an illness or on a medicine known to cause hair loss, 823 women were left.

The team used trichograms, which means pulling a small sample of hairs and checking what phase each root is in. They found the highest share of resting (telogen) hairs in summer, a smaller second peak in spring, and the lowest share in late winter.

Two things are worth knowing. First, this study measured the share of resting hairs, not how many hairs fell out. Second, these were women who had already come to a clinic about hair loss, so they may not match the general public. Still, a summer peak in resting hairs fits with more hairs falling out in the months that follow.

A study of Google searches

A 2018 letter in the British Journal of Dermatology, Hsiang and colleagues, looked at Google Trends data from 2004 to 2016. According to Live Science's report on the study, searches for "hair loss" peaked in summer in eight English-speaking countries, including the UK, with autumn close behind, and were lowest in spring.

The obvious catch: searching for hair loss is not the same as having it. People could be searching for many reasons. It's a hint that more people notice or worry about hair loss in summer and autumn, not proof.

So why does hair fall out more in autumn?

Put together, the studies point to the same rough pattern. More hairs enter the resting phase in summer, and they shed in late summer and early autumn. Nobody has proven why. The researchers in the Google study suggested factors such as UV index might play a part, but that was an idea, not a finding.

You'll see other reasons online, like shorter days, colder weather or central heating drying your hair out. None of the studies we opened tested those, so we can't tell you they cause shedding. Dry, brittle hair can snap, which is different from hair falling out at the root, but that's a separate issue.

Hair shedding in October: normal or not?

The UK study found the peak in August and September, so some extra shedding running into October is in line with that pattern. By late autumn and winter, the research suggests shedding should settle back down.

It's also worth thinking back about three months. The British Association of Dermatologists' leaflet on telogen effluvium says this type of heavy shedding can start around three months after a trigger. Common triggers include illness with a high fever, childbirth, surgery, big weight loss or extreme dieting, stressful life events, starting new medicines and stopping hormone treatment such as the pill. A summer bug, a stressful July or a crash diet before a holiday could show up as shedding in October.

The same leaflet says the shedding phase usually lasts three to six months and usually gets better without treatment. It counts as chronic if it goes on for more than six months.

Signs it might not be seasonal

Seasonal shedding should be spread across the whole scalp and should ease off within a few months. These signs point to something else:

• shedding that keeps going past winter, or for more than six months

• bald patches, a widening parting or a thinning crown (seasonal shedding tends to be all over)

• an itchy, flaky, red or sore scalp

• hair snapping partway down the length, with no root on the end

• you also feel unwell or run down in other ways

Iron deficiency and thyroid problems are two of the causes the BAD leaflet says blood tests check for. Our guide to why your hair is falling out covers ten common causes in more detail.

What to do if you're worried

Start by keeping a rough record for a couple of weeks. Look at the hair in your brush, on your pillow and in the shower. Photos of your parting and hairline in the same light, a month apart, are more useful than a single panicked look in the mirror.

If you feel unwell, or you've noticed any of the signs above, see your GP. The NHS says to see a GP if you're worried about your hair loss, and a GP can arrange blood tests. A pharmacist can help with flaky or itchy scalp problems.

If you'd like someone to look closely at your scalp and hair, we offer a hair and scalp analysis in Belfast with our trichologist, Theresa Anthony. It can help tell the difference between normal shedding and thinning that needs more attention.

Frequently asked questions

Is seasonal hair loss real?

There is some evidence for it. A small UK study found shedding peaked in August and September, and a larger Swiss study found the most resting hairs in summer. The studies are small and none proves the cause.

How long does autumn hair shedding last?

The research suggests extra shedding peaks in late summer and early autumn, then drops in winter. Shedding that lasts more than six months is called chronic telogen effluvium and is worth checking.

Is seasonal hair loss in the UK different from elsewhere?

The best-known study was done in Sheffield, so it reflects UK seasons. The Google search study also found a summer and autumn peak in UK searches. There's no good evidence yet on how much location changes things.

Will my hair grow back after seasonal shedding?

Seasonal shedding is part of the normal hair cycle, so new hairs usually grow from the same follicles. Regrowth takes months to show because hair grows slowly.

Book a hair loss consultation in Belfast

If the shedding hasn't settled or you'd like peace of mind, you can book a £30 hair loss consultation at Tess Hair and Scalp Clinic, 77a Botanic Avenue, Belfast. You can see all our treatments and prices online, or call 028 9096 4731.

Sources: NHS: hair loss · Randall and Ebling 1991, British Journal of Dermatology · Kunz, Seifert and Trüeb 2009, Dermatology · Hsiang et al. 2018, British Journal of Dermatology · Live Science report on the Google Trends study · British Association of Dermatologists: telogen effluvium

About the author: Theresa Anthony is the trichologist at Tess Hair and Scalp Clinic, 77a Botanic Avenue, Belfast BT7 1JL, where hair loss treatment and a full hair salon sit under one roof. More about Theresa.

Written with AI help using the sources above, then checked by Theresa Anthony or her team before it went live.