Winter Dandruff: Why It Gets Worse and What Actually Helps

Flakes that get worse in winter can be a dry scalp or dandruff caused by yeast. How to tell them apart, which ingredients work, and when to see a doctor.

Winter brings dry air, hot showers, woollens rubbing against the neck and, for many people, white flakes on dark clothes. Not every flaky scalp is the same, though, and the right fix depends on which one you have.

Dry scalp or dandruff?

The two get mixed up all the time.

Dry scalp: small, white, dry flakes. The scalp itself feels tight and may itch a little. Skin on your arms and legs is often dry at the same time. It's caused by low moisture, and it usually gets better with gentler washing and a moisturising routine.
Dandruff: larger, slightly oily or yellowish flakes, often with an itchy, greasy-looking scalp. It's linked to a yeast called Malassezia that lives on everyone's scalp, and to how your skin reacts to it. Dandruff tends to come and go and often flares in winter and with stress. When it's more severe, with red, inflamed patches, it's called seborrhoeic dermatitis.

If you can't tell, the washing test helps: if flakes improve with a simple anti-dandruff shampoo, it was likely dandruff. If they get worse or your scalp feels even tighter, it was probably dryness.

Why winter makes it worse

Cold, dry air pulls moisture from the skin, including the scalp.
Hot showers strip oils and irritate.
Washing less often in the cold lets flakes and oil build up, which feeds the yeast.
Hats and woollens trap sweat and rub the scalp.
Less sunlight and more stress in some people's routines.

Ingredients that work for dandruff

Anti-dandruff shampoos work in a few different ways. These are the active ingredients with the best track record:

Ketoconazole (usually 1% to 2%): an antifungal that reduces the yeast.
Zinc pyrithione: antifungal and antibacterial, widely available.
Selenium sulfide: slows the turnover of skin cells and reduces yeast. It can discolour light or treated hair, so rinse well.
Ciclopirox: another antifungal, often in prescription-strength products.
Salicylic acid: helps loosen thick flakes, but can dry the scalp if overused.
Coal tar: effective but strong-smelling and not for everyone.

Check the label to see which of these a shampoo contains, since the brand name tells you nothing. If you're unsure, a pharmacist can help you choose.

How to use them properly

Wet your hair and apply the shampoo to the scalp, not the lengths.
Massage it in with your fingertips (not nails), then leave it on for three to five minutes. This is the step most people skip, and it's where the active ingredient works.
Rinse with lukewarm water, and follow with a conditioner on the lengths only.
Use it two or three times a week until the flakes settle, then once a week to keep things under control. Some people do better rotating two different active ingredients.

What to change in your routine

Don't stop washing. Two or three washes a week is a sensible minimum for most scalps, more if it's oily.
Use lukewarm water. Hot water irritates the scalp and pulls moisture.
Be careful with heavy oils. Leaving coconut or other oils on an already flaky scalp can make dandruff worse for some people, since Malassezia feeds on certain fats. If an oil massage helps you, wash it out within a few hours rather than overnight.
Don't scratch or pick. It breaks the skin and can cause infection.
Wash hats, scarves and pillowcases regularly.

The same yeast is behind fungal acne on the face, which is why oils and fatty ingredients can matter in both. Our fungal acne guide explains the ingredient side, and our ingredient checker can scan a hair or skin product's label.

When to see a doctor

Your scalp is red, sore, oozing, or has thick crusted patches.
Flakes spread to eyebrows, the sides of the nose, behind the ears or the chest.
You've used an anti-dandruff shampoo correctly for about four weeks without improvement.
You notice hair thinning or patchy hair loss. Dandruff alone doesn't usually cause hair fall, and our guide to seasonal shedding explains what's normal.

Quick answers

Is dandruff contagious?

No. The yeast is already on everyone's scalp.

Can I use anti-dandruff shampoo every day?

Some can be used more often, but start with two or three times a week and read the label. Daily use of medicated shampoo can dry hair out.

Does dandruff cause hair loss?

Not directly. Scratching hard or a severe inflammatory condition can damage hair, so see a doctor if you notice thinning.

This is general information, not medical advice.