Medically reviewed by Vicky Davis, FNP
Written by Our Editorial Team
Last updated 9/9/2019
Despite what the “keto” in the name might suggest, ketoconazole doesn’t have anything to do with fad diets.
The shampoo ingredient has health benefits though, especially if you’re experiencing certain types of hair loss.
Ketoconazole is an antifungal medication, and it’s commonly seen in shampoos that treat certain types of hair loss.
As we’ll explain later, it's an effective tool at fighting off certain causes of hair loss, within limited circumstances.
But while any effective tool is a good tool, ketoconazole shampoo also comes with some potentially serious side effect warnings.
For fungal infections, it’s a big gun with a lot of side effect risks that you should be aware of.
Oh, and as a hair loss tool, it’s only part of the picture. But before we get into that though, it’s probably helpful to do a brief refresher on hair loss in general.
Hair loss, put simply, is the breakdown of normal function in your hair’s natural growth cycle.
Every one of your hair follicles is operating independently in different parts of a three-phase cycle, consisting of three “growth” phases called the anagen phase, the catagen phase, and the telogen phase.
This is a good time to mention that, when it comes to hair, losing it doesn’t always mean losing it for good. Hair loss is actually something you experience every day — those lost soldiers in the drain, on your collar, and around the pillow actually are part of the normal cycle of growth and loss.
According to the American Academy of Dermatology (AAD), a normal person can shed approximately 100 strands of hair daily ( from around 100,000 total) and still be in the normal segment of the population.
So, the hair phases are key to understanding this.
And your hair is going through all three of them right now. Some 90 percent of your hair follicles are currently in the anagen phase, which is the growth phase.
As they come to the end of this segment, they’ll transition into the resting “catagen” phase, where they’re alive but no longer producing more hair.
Finally, they’ll enter the telogen phase. About nine percent of your hair is in this phase now and at any given time, assuming everything is working the way it needs to.
So, in the simplest terms, hair loss is what happens when these phases are either interrupted, stopped or the proportions come out of balance.
Ketoconazole is an antifungal medication commonly placed in shampoos to treat a condition called seborrheic dermatitis — a condition that causes skin irritation and flaking, and in its mildest form is responsible for dandruff.
Ketoconazole shampoo is an effective treatment for this condition, and has been shown in multiple studies to be a superior treatment over comparable options.
In other words, this stuff is pretty good at treating mild and serious seborrheic dermatitis.
It’s also an effective medication for treating other fungal infections or problems that are worsened by fungal infections, such as diaper rash, eczema, impetigo, psoriasis and tinea manuum.
As with most topical medications (and particularly ones that go on your head) it’s best to try a small amount in one location first when you begin using it.
Once you can confirm no serious or immediate reactions, you can apply the shampoo normally, and follow directions on the product label.
According to the U.S. National Library of Medicine, ketoconazole shampoo may cause several side effects, most of which present as some sort of skin irritation.
Changes in Hair Texture
Blisters on the Scalp
Oily or Dry Hair or Scalp
Irritation, Itching or Stinging Where the Medication was Applied.
These side effects are considered milder, and you should tell your healthcare provider if they become severe or do not go away.
More serious side effects are reasons to call your healthcare provider immediately. They include:
Difficulty Breathing or Swallowing
Redness, Tenderness, Swelling, Pain or Warmth in the Place You Applied the Medication
The National Library of Medicine also suggests that other side effects may occur that are not listed — if you experience anything unusual, it’s best to call a healthcare professional to discuss and report the symptoms.
Lastly, ketoconazole has a serious poison warning for swallowing.
A little bit of touching your lips in the shower may not be a big deal, but if you or a child happen to accidentally swallow ketoconazole shampoo or cream, you should call the local poison center immediately.
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You may be reading this because you’ve been shown some evidence that ketoconazole shampoo can be an effective treatment for hair loss, and while that’s potentially true in some rare circumstances, this medication should not be considered primarily a hair loss treatment.
Ketoconazole has been shown to have some benefits when used alongside other hair loss medications.
But unlike finasteride, neither the FDA nor any other organization has recognized ketoconazole as a DHT blocker or as a hair loss treatment — that’s a myth, and it’s one of several ketoconazole myths you can read about in our guide, Truths and Myths about Ketoconazole.
Studies show daily finasteride can reduce DHT levels by as much as 70 percent, leading to a reduction and potential reversal of male pattern baldness hair loss.
Minoxidil, however, is thought to work by encouraging dormant follicles to grow hair again.
Studies show that over a 48-week period, minoxidil increased the thickness of and total hair count in participants by as much as 18 percent.
Those medications are oral and topical, respectively, but there are also shampoo options as well.
Our What to Look For in a Men’s Hair Loss Shampoo guide is a great place to learn more about what shampoo ingredients can help with hair loss.
If you have dandruff problems or more serious fungal issues, ketoconazole shampoo is an effective medication to help get that under control.
If you’re experiencing hair loss, there are other avenues you should go down.
We’ve recommended minoxidil and finasteride above, which will cover various forms of hair loss.