Ketoconazole shampoo is a medicated shampoo designed to treat fungal infections that affect your scalp. You can use it to treat conditions such as stubborn dandruff and psoriasis.

Shampoos containing ketoconazole are available both over the counter (OTC) and by prescription from your doctor.

Ketoconazole shampoo can help treat a range of conditions, including those below.

Seborrheic dermatitis

Ketoconazole shampoo is commonly advertised as a dandruff treatment, with OTC brands like Nizoral available for purchase in supermarkets or online. Dry scalp causes some dandruff, but other dandruff can be due to seborrheic dermatitis.

Seborrheic dermatitis may be associated with an overgrowth of Malassezia, a yeast fungus that’s naturally present on your skin. Ketoconazole can help treat dandruff by reducing the fungus and decreasing inflammation.

Psoriasis

Ketoconazole is a common treatment for psoriasis, another inflammatory skin disease that causes skin flaking, skin plaques, and redness or other skin discoloration. Yeast-like fungus often infects these skin plaques. Prescription ketoconazole may be necessary to treat psoriasis flares.

Tinea infections

Ketoconazole shampoo can also treat tinea capitis and tinea versicolor. Tinea capitis is a superficial, ringworm-like fungus infection that can affect your scalp. Tinea versicolor is a skin infection caused by overgrowth of a type of yeast that naturally lives on your skin.

Hair loss

While ketoconazole is most often used for its antifungal properties to treat infections or conditions such as seborrheic dermatitis, some evidence suggests that it may also help promote hair growth or reduce hair loss. However, more research is necessary to investigate this possibility.

Multiple types of ketoconazole shampoos are available OTC and by prescription from a healthcare professional.

OTC ketoconazole shampoos contain 1% or less of ketoconazole. The most commonly known OTC brand is Nizoral, which is available in most supermarkets and online.

You can get shampoos that contain 2% or more of ketoconazole with a prescription from your doctor. Brands available by prescription include:

  • Ketozal
  • Ketozolin
  • Ket Med

Before using ketoconazole, you should be aware of the side effects it may cause.

One of the most common side effects is skin irritation, which can take the form of pimple-like bumps on your skin where you’ve used the product. Ketoconazole shampoo might also cause oiliness or dryness of your hair or scalp, changes in hair texture, or discoloration.

If your hair is permed, ketoconazole may cause your hair to lose its curl.

In rare cases, ketoconazole shampoo can result in hair loss. Talk with your doctor right away if you notice this side effect.

Symptoms of allergic reaction

Allergic reactions to ketoconazole shampoo are extremely rare but should be taken seriously. Seek medical attention right away if you have symptoms of an allergic reaction, such as:

  • severe itching
  • swelling of your face, tongue, or throat
  • difficulty breathing
  • rash
  • dizziness

Anaphylactic reactions and other severe hypersensitivities have also been reported with ketoconazole use.

Other considerations

Ketoconazole’s effects in people who are pregnant or breastfeeding have not been well studied. If you’re pregnant and have concerns about using an antifungal treatment, talk with your doctor before using even the OTC version of this antifungal shampoo.

The safety of ketoconazole in children has not been well studied, either. It’s best not to use ketoconazole shampoo on children under 12 years of age unless instructed to do so by their pediatrician.

You should use a ketoconazole shampoo as instructed by your doctor or as indicated on the product label.

To use it on your scalp, apply the shampoo to wet hair. Lather it well and give it time to soak into your scalp before rinsing. You can then condition the ends of your hair, rinse, and dry as you usually would.

If you’re using ketoconazole shampoo on an area other than your scalp, apply it to the affected area and let it sit for 5 minutes. Wash it off thoroughly with water, and then dry your skin.

How often and how long you’ll use the shampoo will depend on several factors, such as:

  • the strength of the shampoo (1% for the OTC version or 2% for the prescription version)
  • the condition you’re using it to treat
  • the severity of your current symptoms

Based on these factors, your doctor might ask you to use the shampoo anywhere from every other day to once per week.

Use ketoconazole shampoo exactly as your doctor recommends. Do not use it more or less frequently than your doctor tells you to.

You should start to see results within 2 to 4 weeks after you begin using the shampoo, unless your doctor tells you otherwise for your particular condition. If you don’t see any improvement after a month, ask your doctor whether a different treatment option is necessary.

If ketoconazole shampoo doesn’t work to treat your skin condition, you might need to try an alternative. Options might include other medications, such as oral antifungals, to help treat your overall condition or more widespread infections.

There are also other medicated shampoos that you can try. These include: