Hair Smells Like Mildew: What Should I Do?

A reader who requested to remain anonymous wrote in with the following:

This is so gross, but I've noticed my scalp has started to smell like a moldy towel. It's become really embarrassing. I've been trying to hide it with scarves and hats that smell very strongly of a nice smelling laundry detergent but I would really like for this problem to go away ASAP. I don't think it's because my hair is dirty, because it doesn't look greasy - I've never struggled with hair that looks greasy. My hair is typically actually pretty dry - I have curly hair, and use a few curl creams to shape it (sharing in case that's helpful). I have an appointment with a dermatologist to help, but it's not for a few weeks. The issue has only started since summer hit, so I'm wondering if it might have something to do with the heat. Any advice?

Thanks for writing! Oof, this is not a fun problem to have - we feel for ya. We've got a lot of thoughts about what you can do to help - we hope you find our ideas helpful!

You might need to wash your hair more

How often are you washing your hair? Even if your hair doesn't look visibly greasy, buildup is still accumulating on your scalp.

Not washing your hair frequently enough allows for dead skin cells, pollutants (such as dirt and dust), sweat, styling products, and sebum (the oil produced by your scalp) to build up on your scalp. All of these guys combined can create a film on your scalp that can throw the microflora on your skin out of whack.

Yeast, specifically Malassezia yeast, thrives in this kind of environment. It eats sebum, so when you don't wash your hair, you give it plenty to feed on. The dirt/styling product/sweat/sebum film provides it with shelter, so it's able to grow unchecked and get stinky.

As gross as this probably sounds, we also want to note that a normal amount of Malassezia yeast on your scalp is nothing to worry about. We're all covered with teeny-tiny bugs, and this is just one of them. Usually, those bugs are able to exist in harmony, without producing an odor.

A stinky smell is a sign that things are getting messed up, and that you need to hit the reset button by hitting the shower.

Change the way that you're washing your hair

Even if you're washing your hair frequently, you might not be adequately cleansing your scalp.

When you wash your hair, gently yet thoroughly scrub your scalp with the pads of your fingertips. Focus on getting a good lather from your shampoo, and keep the suds at your scalp, rather than on the ends of your hair.

When you shampoo, you should be spending the majority of your time working on your scalp. The scalp is much trickier to clean than your ends, since scalps are fairly prone to buildup (gotta keep that yeast in check).

Make sure you don't scratch your scalp with your fingernails, since this could worsen the condition of your scalp - if this keeps happening unintentionally, you might need to trim your nails.

Cut down on the styling products...

Remember that bit about how malassezia yeast eats sebum? It finds sebum to be tasty because sebum is made of lipids, AKA fatty acids. Malassezia yeast isn't picky - it'll also swallow up styling products that are heavy on lipids, such as creams and waxes. And even if you use styling products that don't contain lipids, your products will still contribute to the buildup that provides shelter to the yeast. So if you don't want to give extra fuel to the stinky fire, cut down on styling products.

..And the hats/headbands/scarves

Look, we think hats are super useful. They can help prevent sun damage, and we're all about preventing sun damage. So by no means are we anti-hat.

Unfortunately, hats trap heat and moisture close to the head, making your scalp extra humid. The same thing happens with tight-fitting headbands - the area that's covered doesn't get good air circulation, and the skin gets extra toasty.

In an effort to cool down, the skin generates sweat, the sweat mixes with sebum, and, well, you know where this is going. Not only does the malassezia yeast LOVE the heat to begin with, it also gets an extra tasty snack. So if you want to fight the stink, break up with your hat for a little bit. If that's not possible, switch to one made of a more breathable fabric, or, at the very least, wash it frequently.

Switch up your shampoo

You might be using a shampoo that either over-cleans your hair - scalps don't like to be stripped of oil, so when you use a shampoo that cleanses your hair too aggressively, your scalp gets the message to start producing a whole lot of sebum to re-grease it. On the other hand, you might be using a shampoo that under-cleanses your hair - it might not be powerful enough to clear out the yeast. You might even be using a product that's messing with the pH balance of your scalp, which would really send your microflora into a tizzy (pro tip - shampoo bars are not pH balanced. If your hair is smelly and you use a shampoo bar, we would really recommend you make a switch to a sulfate-free shampoo instead.)

We recommend purchasing a sample-sized bottle of high-quality shampoo (hey, we make those!) to see if a product switch will help do the trick.

Use an over-the-counter aid to prevent excessive sweating on the scalp

Have none of the above helped out with the mildewy smell coming from your scalp? You might have a problem with excessive sweating.

Your scalp, just like the rest of your body, produces sweat in an effort to cool itself down when it's overheated, and some bodies happen to produce an unusually large amount of sweat when overheated - no big deal, we're all different! The only problem is that, like we said before, yeast thrives in the presence of sweat, making that yucky mildewy odor.

Fortunately, there are a lot of different things you can do to help improve this condition. You might already be familiar with Certain Dri - this is an over-the-counter, topically-applied product that can help the body to decrease the amount of sweat it produces. It's not a miracle worker, but it can certainly help make a difference. Certain Dri, as well as other product lines that function similarly to it, comes in many different forms, including one that's made specifically for scalps.

Do what you can to keep yourself cool during the day

Not interested in using an over-the-counter aid to prevent excessive sweat? Again, no biggie. You can go for a basic solution, and do what you can to keep yourself cool during the day. Keep a small fan at your desk, pointed at your face to improve the air circulation around your head. Wear breathable fabrics - even if you work in a conservative office environment, you can wear performance fabrics that are made of sweat-wicking materials.

Though this might not make a huge difference in the mildewy smell, cooling down your body temperature to prevent sweat definitely won't hurt.