Premature grey hair: causes and what is known

Grey hair is a natural part of ageing, but some people notice it much earlier than friends or siblings. In Malaysia, "uban awal" is a common worry among students and young working adults. Here is what is known.

What counts as premature greying?

Greying happens at different ages in different populations. A 2024 review notes that greying is often called premature in people of European descent when it starts before about 20, and in people of African descent before about 30. There is no well-defined age threshold for Asian populations ¹. In practice, if you are greying much earlier than others in your family or peer group, it is reasonable to look into it.

Why hair turns grey

Hair colour comes from melanin, made by pigment cells (melanocytes) in the hair follicle. Over time, these cells become less active or are lost, and new hairs grow in with less pigment. Researchers think oxidative stress, a build-up of damaging molecules in the pigment cells, plays a part ¹. Greying does not damage the follicle's ability to grow hair; grey hairs grow normally.

Possible causes and links

Premature greying usually results from a mix of genetic, environmental and cellular factors ¹.

• Family history. This is the strongest factor. If parents or grandparents greyed early, you may too.
• Vitamin B12 and other nutrients. Studies have linked premature greying with low vitamin B12, and some have found lower ferritin (stored iron), calcium or vitamin D in young people with grey hair ¹. Vitamin B12 deficiency also causes tiredness and other symptoms and is worth checking ².
• Thyroid problems. An underactive thyroid has been linked with early greying ^{1 3}.
• Smoking. Smoking is listed among external factors in research on greying ¹. It is one more reason to quit. See smoking and hair loss.
• Stress. Psychological stress is often blamed. It is listed as a possible factor, but the evidence in humans is limited ¹.
• Localised white patches. A patch of white hair with pale skin underneath can be vitiligo, which needs a doctor's assessment ¹.

Studies on links between grey hair and other health problems, such as bone density or heart disease, have shown mixed results ¹. Early grey hair on its own is not a sign that you are unhealthy.

Which tests may help?

If greying is very early or comes with other symptoms, your doctor may suggest blood tests, such as:

• Full blood count
• Vitamin B12 and folate
• Ferritin (iron stores)
• Thyroid function
• Vitamin D

See blood tests for hair loss and vitamin D and hair. Treating a true deficiency is good for your general health. In a few reported cases, correcting a deficiency was followed by some return of colour, but this is not reliable.

Can grey hair turn black again?

Grey hair usually advances gradually and tends to stay grey, although occasional natural return of colour has been reported ¹. The 2024 review concluded that effective, evidence-based treatments for premature greying are still lacking ¹. Be cautious of supplements, oils or herbal remedies sold to "reverse" grey hair. Some herbal products, such as he shou wu, have been linked with liver injury ⁴. See is he shou wu safe?.

Practical options

• Accept it. Many people now embrace grey or silver hair as a style.
• Hair colour. Long-lasting and wash-out hair dyes and henna are the most reliable way to cover grey. Hair dyes can cause allergic reactions, mainly to paraphenylenediamine (PPD), so do a patch test 48 hours before each use ⁵.
• Gentle routine. Grey hairs can feel coarser and drier. A gentle conditioner helps.
• Do not pluck. Plucking does not make more grey hairs grow, but repeated plucking can damage follicles over time.

When to see a doctor

See a doctor if greying is very early and sudden, comes with tiredness, numbness, weight change, or feeling cold, or if you have white patches of hair with pale skin underneath ⁶.

The bottom line

Premature greying is mostly genetic. Sometimes it is linked to low vitamin B12, thyroid problems or smoking, which are worth checking. There is no proven way to restore colour, so be wary of products that promise it. Colouring, or simply embracing it, are both reasonable choices.

Frequently asked questions

At what age is grey hair considered premature in Asians?

There is no well-defined age threshold for Asian populations; it is usually judged against family and peers ¹.

Can vitamin B12 deficiency cause grey hair?

Studies have linked premature greying with low vitamin B12, so it is worth checking ^{1 2}.

Can grey hair turn black again?

Occasionally colour returns naturally, but effective evidence-based treatments are lacking ¹.

Does plucking grey hair make more grow?

No, but repeated plucking can damage follicles over time.

Educational content. Not medical advice.