Dandruff

Dandruff needs no introduction. If you’ve watched TV in the last twenty years, you’ve probably seen a commercial where a man finds the shoulders of his black T-shirt covered in white flakes and ponders what to do about it. (Spoiler alert: He starts using dandruff shampoo and then probably smiles.)

If you’re wondering how your life started to resemble this ad, what causes dandruff, and how to treat it, then — hello! — you’re in the right place.

Here, we’ll cover what dandruff is, its causes, and, most importantly, what you can do to treat it, including shampoo recommendations and at-home remedies (pass the tea tree oil).

Dandruff is a common scalp disorder that can affect anyone at any time. It often coincides with hormonal changes in young adulthood and continues into middle age (and is less common among older people). Research shows that men are more likely to get dandruff than women.

Dandruff is often thought to be dry, flaky skin. Many people confuse a dry scalp with dandruff, but they’re actually not the same thing.

So what is dandruff, exactly? Generally, dandruff looks like oily or shiny flakes that are yellow or white, though sometimes they may have a reddish tinge. Unlike dry skin, which causes smaller flakes (think finely grated parmesan cheese), dandruff flakes are larger (think flake salt) and sometimes crusty.

If you have dandruff, you’ll probably see flakes not only on your hair but also on your clothes or in your brush.

While most dandruff looks similar, a few things can cause it:

• Malassezia build-up

• Seborrheic dermatitis

• Oily build-up

We’ll explain these in more detail below.

Malassezia Build-Up

Malassezia is a harmless fungus everyone has on their scalp — it’s part of the skin’s normal flora. It’s actually an umbrella term for several types of fungus.

But if everyone has Malassezia, why doesn’t everyone have dandruff? Great question.

Dandruff is caused specifically by an overgrowth of Malassezia, meaning there’s too much of it on the scalp.  A 2014 study found that a high density of Malassezia species on the scalp was related to the severity of dandruff.

While dirty or oily hair on its own isn’t enough to cause dandruff, Malassezia feeds on sebum — so more oil equals more Malassezia.

To make matters trickier, after Malassezia essentially eats the fatty acids in sebum, it leaves behind a byproduct called oleic acid. Research shows that some people are more sensitive to oleic acid, and to get rid of it, their dead skin cells turn over quickly, causing flaking and shedding.

Seborrheic Dermatitis

Seborrheic dermatitis is a common skin disorder worldwide. The condition affects up to 70 percent of infants (it’s called cradle cap in babies) and roughly 12 percent of the general population. Dandruff is a mild form of seborrheic dermatitis.

Though Malassezia is a leading factor in why seborrheic dermatitis develops, other things can cause it.

Additional risk factors that make someone more likely to have seborrheic dermatitis include:

• Bacteria growth or exposure

• Chronic stress

• Genes

• Hormones

• Nervous system disorders like Parkinson’s disease

• A weakened immune system, potentially caused by HIV infection

Low temperatures and a lack of humidity also play a part, which is why dandruff often flares in winter.

Oily Build-Up

Yeast isn’t the only cause of an oily scalp.

Here’s what can cause oily build-up on the scalp:

• Not shampooing regularly enough

• Not using enough shampoo

• Allowing sweat to accumulate

• Not thoroughly rinsing out hair products can

Some people have excess oil on their scalps, and while their hair may look a little greasy, they won’t get dandruff. But if you have too much yeast on your scalp paired with this oil build-up, it can result in dandruff.

Dandruff is tricky because it can be caused by one thing or some combination of oil secretion, fungal colonization, and an individual susceptibility to the condition.

If you’re not seeing improvements in dandruff, get in touch with a dermatologist or healthcare professional. They can figure out if you have dandruff or another scalp condition like psoriasis, eczema, tinea capitis (scalp ringworm), or contact dermatitis, which can also cause flaking and scalp itching.

The good news is that dandruff is fairly easy to treat. It shouldn’t require much more than switching up your shampoo or making easy lifestyle tweaks. Here’s how.

Use Dandruff Shampoos

That guy in the dandruff commercial was onto something. One of the easiest and most effective ways to clear up dandruff is to lather up with anti-dandruff shampoo.

Shampoos with active ingredients like pyrithione zinc, ketoconazole, selenium sulfide, coal tar, and salicylic acid are the gold standards in treating dandruff.

Here are the cliff notes on the best shampoos for dandruff:

• Pyrithione zinc and salicylic acid. Our dandruff detox shampoo contains 1% pyrithione zinc and salicylic acid. This medicated shampoo reduces build-up on the scalp, calms itchiness and irritation, and treats flaking, while argan and avocado oil nourish and moisturize. A 2018 study found that herbal zinc pyrithione shampoo and scalp lotion improve symptoms of seborrheic dermatitis.

• Ketoconazole. Ketoconazole has antifungal and anti-inflammatory properties. According to research, 2% strength seems to be the sweet spot to decrease Malassezia colonization.

• Salicylic acid and sulfur. Shampoos with salicylic acid and sulfur help loosen scales so they can be washed off.

• Coal tar. Dermatologists sometimes suggest coal tar shampoos for treating dandruff and redness caused by seborrheic dermatitis. However, they aren’t widely recommended because coal tar can cause irritation and increased sun sensitivity. (Using it once or twice a week might be a good cadence with minimal irritation.)

• Selenium disulfide. One study found that selenium disulfide-based shampoo applied for four weeks “significantly improves dandruff and seborrheic dermatitis.”

To get the most out of anti-dandruff hair washes, follow the directions closely. Many advise leaving the shampoo on for several minutes before rinsing. Other formulas are meant to be used only a few days a week.

Try Home Remedies

If you treat your bathroom like an apothecary (or you just don’t feel like going to the drugstore), these home remedies show promise in treating dandruff.

Tea Tree Oil

There’s actually a fair amount of research backing tea tree oil as a natural remedy for dandruff, though none of the studies are super strong (many had small sample sizes, lacked a control group, or were only done on animals).

But here’s what we know.

• Tea tree oil might be a gentle, effective option. A review of several studies showed that a shampoo containing 5% tea tree oil was well-tolerated and seemed effective in the treatment of mild to moderate dandruff.

• It’s a natural fungus remedy. One 2021 study found that tea tree oil shampoo had antifungal properties. However, it’s important to note that the shampoo also contained sodium lauryl sulfates and salicylic acid, so it’s hard to give all the props to tea tree oil itself.

You can buy shampoos already formulated with this essential oil. Or consider adding a few drops of pure tea tree oil to your existing shampoo.

Coconut Oil

Coconut oil is a bit of a miracle worker when it comes to natural remedies. One study (that was only eight weeks long) found that applying coconut oil directly to the skin decreased symptoms of atopic dermatitis (eczema) by 68 percent.

In a separate study on 140 women, coconut oil applied to the scalp seemed to improve the scalp microbiome, which could theoretically help reduce dandruff.

Aloe Vera

Beyond soothing sunburn, aloe vera may benefit hair health. A 2015 study suggested that its antibacterial and antifungal properties could help prevent dandruff.

Look for shampoos containing this ingredient, or apply aloe vera gel directly to your scalp.

Aspirin

Looking for a dandruff treatment on the fly? Aspirin contains salicylic acid — it’s what makes the drug anti-inflammatory. For that reason, salicylic acid is often found in acne treatments and anti-dandruff shampoos.

If you’re in a pinch or don’t feel like running to the drugstore, you could try crushing one or two aspirin tablets and mixing them into your normal shampoo.

Be Mindful of Lifestyle Factors

Lifestyle factors matter, too, like how much sun you get, what styling products you use, and what you eat.

Sun Exposure

If you have dandruff, you’ll probably want to get a little bit of sun, but not too much. We’ll explain.

Some research shows that UVA and UVB rays from the sun can actually help treat seborrheic dermatitis. How? They kill yeast.

But you don’t want to get a sunburn, which can make scalp flaking worse (among many, many other reasons to avoid sunburn).

Certain dandruff shampoos, especially those containing coal tar, can make skin more sensitive to the sun (you may see it called “photosensitivity” on a warning label). So it’s vital to wear protective hats and scalp sunscreen if needed.

Styling Products

You want your hair to look a particular way, and it takes products to get that perfect flip or fauxhawk. Good news: Hair products don’t directly cause dandruff, so you can keep your trusty arsenal of haircare — just be sure to rinse thoroughly.

But as mentioned, product build-up can become dinner for Malassezia bacteria. In addition to dandruff shampoo, it can help to occasionally use a clarifying shampoo containing extra soap ingredients to reduce build-up and get the scalp super clean.

Diet

What you eat matters. We know you’ve heard this one before, and for the record, a few trips through the drive-through aren’t going to cause dandruff. But hear us out.

A large 2019 study with over 4,000 participants found that high fruit intake was associated with a lower instance of seborrheic dermatitis. Meanwhile, those who ate diets high in added sugar and processed foods were more likely to have the scalp condition.

Eating a diet rich in protein, zinc, iron, biotin, and a wide variety of other vitamins and minerals is crucial for overall hair health.

Is dandruff bad? Good question. Dandruff isn’t contagious or a serious health condition.

But you’ll usually want to treat dandruff right away because it can be itchy, distracting, or keep you from feeling your most confident.

If you don’t treat dandruff, it can set off a potential cascade of other issues.

Itching and Redness

The longer you go without treating dandruff, the more scales and flakes will build up. Scratching can be damaging to your hair follicles — one easy trick to minimize damage is to keep your fingernails short.

More Severe Dandruff or Seborrheic Dermatitis

If your dandruff hasn’t already turned into full-blown seborrheic dermatitis, it can become more severe if left untreated.

Unlike dandruff, which is contained to the scalp, research shows that seborrheic dermatitis can potentially spread to other parts of the body, most commonly above the breast bone and near the thoracic spine (upper middle back).

Hair Loss

Some studies suggest that seborrheic dermatitis and dandruff can pose numerous hair health issues, ranging from mild desquamation (that’s shedding) to “honey-colored crusts” attached to the scalp and hair.

If left untreated, it could eventually even lead to alopecia (an umbrella term for hair loss). Other studies have shown that dandruff can happen alongside telogen effluvium (that’s hair loss from stress, illness, or injury). And it might exacerbate androgenetic alopecia, otherwise known as male pattern baldness.

If that last point stops you in your tracks, know it’s very rare for dandruff to cause hair loss. And there are things you can do to stop it from getting to that point.

Interestingly, studies show that anti-dandruff shampoos, specifically those containing ketoconazole, slow the progression of androgenetic alopecia.

Already noticing hair loss from dandruff or a combination of factors? FDA-approved hair loss treatments — like minoxidil, finasteride, or an especially efficacious combination of the two, such as our topical finasteride & minoxidil spray — can help.

If you’re noticing symptoms like an itchy scalp, flakes of skin on your clothes, or scaly patches on your scalp, you’re probably wondering what you can do about dandruff.

Here’s what to keep in mind:

• Dandruff manifests as large, oily, or crusty scales and flakes. It’s caused by several factors, most commonly an overgrowth of a yeast known as Malassezia.

• The good news is that dandruff is easy to treat. Over-the-counter and prescription shampoos containing different active ingredients like zinc pyrithione, salicylic acid, and ketoconazole are designed to treat the fungus largely responsible for dandruff.

• Speak to a dermatologist or healthcare provider if your dandruff worsens or persists after treatments. More serious skin conditions like tinea capitis or scalp psoriasis can mimic dandruff, so your provider can help you figure out what’s going on.

Want to dive further into this topic? Check out our detailed guide on how to get rid of dandruff, and find out more about whether dandruff causes hair loss.