You started applying minoxidil to stop your hair loss, and so far it’s working great. There’s only one problem: the intense itching and flakiness of your scalp.

You feel like you’re left to choose between hair regrowth or a head that doesn’t require constant scratching. You’re convinced you can’t have both.

Fortunately, that’s not quite true. Ketoconazole can help treat dandruff and reduce the side effects of minoxidil—primarily, that annoying flaking and itching. But what does it do, how does it work, and how can you use it? Here’s what you need to know.

What is ketoconazole?

Ketoconazole is a medication that’s used to treat infections caused by a fungus or yeast—think things like ringworm or athlete’s foot. In those cases, it’s available as a cream, foam, or gel.

However, ketoconazole is also available as both a prescription or over-the-counter shampoo that’s specifically designed to control dandruff, as well as scaling, flaking, and itching of the scalp (much like what happens when you’re taking minoxidil).

There’s both 1% and 2% ketoconazole (which refers to the concentration of ketoconazole in the solution). The 1% solution is generally available over the counter, but the 2% version is obviously stronger and requires a prescription from a healthcare provider.

What does ketoconazole have to do with hair loss?

Ketoconazole is generally used to treat the undesirable side effects of other popular hair loss treatments like minoxidil. But can ketoconazole itself actually help stop hair loss? Well, maybe.

Scientific studies and data aren’t totally conclusive about how ketoconazole contributes to hair growth. However, one 1998 study indicated that 2% ketoconazole shampoo increased hair density, as well as the proportion and size of anagen hair follicles, at nearly the same rate as minoxidil regimens.

It’s a promising result. But ketoconazole is only FDA-approved for the treatment of dandruff and seborrheic dermatitis, so it can’t be marketed as a hair loss treatment itself.

How else is it used?

Again, ketoconazole is used in a variety of ways. As the Mayo Clinic explains, ketoconazole cream, foam, or gel is used to treat things like:

  • Athlete’s foot
  • Ringworm of the body
  • Ringworm of the groin
  • Seborrheic dermatitis
  • Sun fungus
  • Yeast infection of the skin

Ketoconazole shampoo is used for dandruff, itching, and flakiness. Studies show that, because it’s stronger, 2% ketoconazole shampoo is often more effective and, as a result, is used for more severe cases of itching and flakiness.

How does it work to treat your scalp issues?

Here’s something you might not know: Dandruff is actually caused by a fungus that’s found on every human head called Malassezia.

But here’s the thing: Malassezia depends on environmental and genetic factors. Everything from hormones to climate, stress, and diet impact the growth of the fungus.

Our scalp cells are constantly renewing (seriously, it’s totally natural), and Malassezia accelerates this renewal process by causing inflammation. So, to put it simply, it increases the cell turnover and the number of dead cells that fall off, which results in itching, flaking, and dandruff.

Because ketoconazole is an antifungal medication, it kills Malassezia, the fungus that causes dandruff in the first place. There you have it—no more scratching flakes off your head.

How do you apply it?

Ketoconazole is shampoo, so it’s only for external use. Of course, it’s always wise to check the packaging to ensure you’re following all directions.

As the Cleveland Clinic explains, you should wash your hands before and after use. Make sure your scalp is thoroughly damp and then apply enough shampoo to cover all of the affected areas of your scalp and work it into a lather.

For the best results let it sit on your scalp for five minutes before rinsing completely with water. Even if you’re using an over-the-counter version, it should be rinsed immediately after it’s lathered.

Much like any other shampoo, be careful not to get the shampoo in your eyes. If you do, rinse your eyes thoroughly with cool water.

How often do you use it?

How often you use ketoconazole shampoo depends on the specific shampoo you’re using, including its concentration and whether or not it’s prescription or over-the-counter. Again, you should read the directions on the label to understand the necessary application frequency.

Usually, prescription ketoconazole is used at least twice a week. Over-the-counter versions can even be used daily.

How long does it take to start working?

There isn’t one right answer for everybody. It depends on the strength of the shampoo as well as the severity of the dandruff that you’re treating. In general, improvement is fast but you often need to continue to use the shampoo to prevent relapses.

Follow the dosage directions on the package or outlined by your healthcare provider, and speak with your doctor if the itching, flaking, and dandruff isn’t clearing.

What are the side effects?

Ketoconazole shampoo is generally safe, but like all medicines, it is associated with some rare but potentially serious side effects.

Get in touch with your doctor right away if you experience any of the following:

  • An allergic reaction like skin rash, itching or hives, swelling of the face, lips, or tongue
  • Pain, tingling, numbness

Other potential side effects can include:

  • Dry skin
  • Hair loss, hair discoloration, or abnormal texture
  • Skin irritation

While those don’t require immediate medical attention, you should speak with your doctor if they’re persistent or have become overly bothersome.

How does it compare to other hair loss shampoos?

It’s important to remember that ketoconazole isn’t actually FDA-approved as a hair loss shampoo and isn’t specifically designed to encourage hair growth. It’s approved to treat dandruff because it kills the fungus Malassezia. And that dandruff causes inflammation, which ultimately can accelerate your hair loss.

The information provided in this article is not a substitute for professional medical advice, diagnosis, or treatment. You should not rely upon the content provided in this article for specific medical advice. If you have any questions or concerns, please talk to your doctor.

*Photo by Jose Soriano on Unsplash