Why Does My Hair Smell Even After Washing? Causes and Fixes
If your hair smells within a day of washing, the cause is usually one of five things: oil and sweat on the scalp that the wash is not fully removing, hair left damp for hours so it develops a musty smell, product build-up that traps oil and odour, a pillowcase, hat or towel that is reintroducing the smell, or a scalp condition such as seborrhoeic dermatitis. The smell almost always comes from the scalp rather than the hair itself. Fixing it usually means washing the scalp more thoroughly, drying hair fully, clearing build-up once in a while and changing fabrics more often. If the smell comes with itching, flaking, redness or soreness, see a pharmacist or GP.
Here is how to work out which cause is yours, and what to change.
Where the smell actually comes from
The hair shaft itself is fairly inert. It absorbs smells from the air, such as cooking, smoke, a crowded pub, but on its own it does not produce odour. The scalp does. It has a high density of oil (sebaceous) glands and sweat glands, and it hosts the normal mix of skin bacteria and yeasts that live on everyone. When oil and sweat sit on the scalp, those microbes break them down, and some of the by-products smell. That is the same basic process behind body odour.
So the question is rarely “why does my hair smell”, and more often “why is my scalp staying oily or damp enough for this to happen so quickly”.
The common causes, in order of likelihood
1. The wash is cleaning the hair, not the scalp
Many men lather the top of the head, rinse, and are done in twenty seconds. The shampoo foams nicely on the hair but never properly reaches the scalp at the back and around the ears, where oil and sweat collect. Short hair is not immune: a dense crop can stop shampoo reaching the skin just as well as long hair can. Our guide to washing hair properly covers the technique; the short version is to massage shampoo into the scalp with your fingertips for at least 30 seconds, section by section, and rinse for longer than feels necessary.
2. Hair that stays damp
Hair that is towelled and left wet under a hat, a hood or a pillow for hours often develops a musty, damp-washing smell. This is especially common with thick hair, which can take hours to air dry in a cold London flat in winter. Drying the roots with a hairdryer, even for a minute, often solves it alone.
3. Product build-up
Waxes, pomades, clays and some silicone-heavy conditioners do not always wash out in one go. Layer upon layer forms a film that holds oil against the scalp and soaks up smells from the air. Hair feels heavy, looks dull, and smells stale faster. A clarifying shampoo every week or two clears it. See our guide to clarifying shampoo.
4. Pillowcases, hats and towels
A pillowcase collects oil and sweat every night. After a week, it puts some of it back. The same goes for a cap, a cycle helmet liner, a beanie or a towel that is used for days and never dries properly. Clean hair on a dirty pillowcase smells by morning.
5. Sweat from training or commuting
A hot Northern line carriage, a cycle up Highgate Hill, a gym session: all of these bring sweat to the scalp. If you wash in the morning and train in the evening, the smell you notice at night is probably fresh sweat, not a failure of your shampoo.
6. A scalp condition
Seborrhoeic dermatitis, which causes greasy, flaky patches and is behind much dandruff, can come with an odour. So can a scalp infection. If you have itching, redness, yellowish or greasy scales, soreness or patches, read the NHS page on seborrhoeic dermatitis and speak to a pharmacist or your GP.
Narrowing it down
| What you notice | Most likely cause | First thing to try |
|---|---|---|
| Musty, damp smell | Hair not drying fully | Dry the roots with a hairdryer after every wash |
| Stale, greasy smell by evening | Scalp not fully cleaned, or build-up | Longer scalp massage; clarifying wash |
| Smell mainly in the morning | Pillowcase | Change it twice a week for a fortnight |
| Smell after hat or helmet | Sweat plus fabric | Wash the liner or hat; let it dry fully |
| Smell with itching and flakes | Scalp condition | Pharmacist or GP |
A one-week reset
- Day one: clarify. Wash with a clarifying shampoo, massaging the scalp in sections, especially behind the ears and at the nape. Rinse for a full minute.
- Change the fabrics. Fresh pillowcase, clean towel, wash hats and helmet liners.
- Dry the roots every time. Hairdryer on medium heat, directed at the scalp, until it feels dry to the touch.
- Use less product. For the week, either none or a small amount of a water-based product that washes out easily.
- Wash as often as you need to. If you sweat daily, washing daily with a gentle shampoo is fine for most scalps.
- Judge it at the end of the week. If the smell is gone, you have your answer. If it persists, or there is any irritation, see a pharmacist.
Things that make it worse
- Masking it with fragrance. Scented sprays layer perfume over the smell and add to build-up.
- Washing less to “train” the scalp. If your scalp is oily and smells, washing less usually makes it worse.
- Scrubbing with nails. Irritated skin is more likely to have problems. Use fingertips.
- Using shower gel instead of shampoo. It is not designed for the scalp and can leave residue in hair.
- Ignoring the beard. Sometimes what smells is the beard, not the head. Our piece on why a beard smells covers that.
Does a haircut help?
Sometimes. Very dense hair dries slowly and makes it harder to clean the scalp; taking out weight or going shorter at the back and sides can make a real difference to how quickly it dries. When you come to the Highgate Cuts barbers, the visit starts with the barber looking at your hair and scalp and asking what you need, and it is fine to mention this. If anything looks like it needs medical attention, we will suggest you see a pharmacist or GP rather than guess. You can see the services on the barber page.
Questions we get asked
Is it normal for hair to smell a day after washing?
A slight natural scent, yes. A strong, stale or musty smell within a day usually points to one of the causes above.
Can stress make my scalp smell?
Stress can increase sweating, which can contribute. It is rarely the only factor.
Should I use an anti-dandruff shampoo?
If you also have flakes or itching, it is worth trying. A pharmacist can recommend one.
Why does my hair smell of smoke or food even though I do not smoke?
Hair absorbs smells from the air easily. A wash removes them.
Book with The Highgate House
Ready for a proper cut? Email us at [email protected] with the service and the day that suits you, and we will come back to you with times.
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The Highgate House, Archway Road, Highgate, London N6.
