Grey hairs in my 20s and 30s: why is this happening?

Grey hairs in your 20s and 30s are more common than most people think. A 2025 survey at Srinakharinwirot University in Thailand found grey hairs in 47% of students aged 25 or under, and in about nine out of ten of them the grey covered less than a quarter of the hair. Hair turns grey when the pigment cells in the root of each hair make less colour. Several studies link early greying with a parent who greyed early, and some studies link it with smoking.

Is it normal to have grey hairs in your 20s and 30s?

It is common, and the numbers are higher than the old idea that grey hair starts in middle age.

What surveys of young adults found

Several surveys have asked young adults about grey hair, or looked at their hair directly. They used different age limits and methods, so the figures are not directly comparable, but they all point the same way.

What the Thai survey found

The Thai study, by researchers in the Department of Pediatrics at Srinakharinwirot University's Faculty of Medicine, is one of the few to look at early grey hair in Thai people. Among students with grey hairs:

• grey hair first appeared at 16.29 years old on average
• in 89.42%, grey covered less than 25% of the hair, by their own estimate
• the mother's history and the father's history of early greying were each significantly linked with grey hair

The students volunteered and answered the questions themselves, and all came from one university, so the figures describe that group rather than all young Thai adults.

When greying usually starts

A 2021 review of hair ageing across ethnic groups reports that the average age when greying starts differs by background: the mid-thirties in Caucasians, the late thirties in Asians and the mid-forties in Africans. A few grey hairs well before that average are still common, as the surveys above show.

What happens inside a hair when it turns grey?

Hair colour comes from melanin, a pigment made by pigment cells called melanocytes in the hair bulb, the root of a growing hair under the skin.

Colour is made while the hair grows

A 2009 review by Desmond Tobin, a hair biology researcher at the University of Bradford, describes the hair's pigment system as one of the body's most visible signs of ageing, with pigment fading in hair long before similar changes show in the skin.

In general terms, each hair gets its colour while it is growing, so a hair that grows with less pigment comes out grey, and one with none comes out white.

Why a grey hair stays grey

A 2021 review of the biology of hair greying explains the process in two stages:

The review notes that there is still no universally accepted model of how human hair greys, and that the size of the genetic part is unclear. A 2024 review adds that grey hair usually progresses gradually and is permanent.

Why do some people go grey earlier than others?

Researchers have looked at many possible factors. Two come up most often in studies of young adults: family history and smoking.

Family history

In the Thai student survey, the mother's history and the father's history of early greying were each significantly linked with early grey hair. The 2020 study from India likewise found the father's and the mother's history among the factors linked with greying before 30. These studies found early greying more often in people whose mother or father greyed early.

Smoking

A 2013 study from the University of Jordan by Zayed and colleagues found that smokers made up 40.2% of the people who went grey before 30, against 24.7% of the others. Smokers first saw grey hair at 31 years old on average, against 34 for non-smokers, and after taking other factors into account smokers were about two and a half times as likely to grey before 30. A 2021 systematic review of 32 studies from the University of California, Irvine concluded that early greying is more common in smokers than in non-smokers. These are observational studies, and they did not look at whether stopping smoking changes grey hair.

Stress

Many people link grey hair with stress. A 2021 study from Columbia University notes that research in mice suggests stress may speed up greying, but that there is no definitive research on this in humans. The researchers developed a way to measure colour along single hairs, like reading tree rings, and found that greying in a hair could happen at the same time as stressful periods its donor reported. It shows that the two can line up in time; it does not show that stress greys everyone's hair.

How strong is the evidence?

If stress has been building up for a while, see Stress keeps building up. How do I spot it and cope?

How do people feel about early grey hair?

For most people it is a matter of looks, but it can still matter. In the Thai student survey, among those with grey hairs:

So about a third felt some effect. If grey hair bothers you, that is a normal reaction, and it is worth knowing that it is shared by many people your age.

What can I do about grey hairs day to day?

Many people choose to leave grey hairs as they are; others colour them. If you colour your hair, these points apply.

Dyeing grey hair safely

The UK's NHS advice on hair dye reactions covers what to check before colouring hair.

Keep a simple note

If you want to talk to a doctor, it helps to note roughly when you first saw grey hairs, where they are, and whether your parents greyed early.

When is it worth seeing a doctor?

If grey hair appears in a patch, or other changes come with it, talk to a doctor. You can also see a doctor any time you are worried.

If your hair is falling out as well, see My hair is suddenly falling out a lot. What do I do first?