Tars for psoriasis

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Tars for psoriasis


Generic NameBrand Name
Coal tar Denorex Extra Strength Medicated Shampoo, Exorex, Neutrogena T/Gel, Psoriasin
Coal tar bath products Doak Tar Oil, Polytar Bath

Tar products that are used to treat psoriasis come in several forms. Coal tar is available as a gel, cream, ointment, liquid, or shampoo. You can get most tar products without a prescription.

Tar therapy usually starts with a product that contains only a small amount of tar. The amount may be increased every few days (unless your symptoms aren't improving or you have side effects).

Tar products may be used with ultraviolet B (UVB) light therapy. This is called Goeckerman treatment. This combination may be given to a person who is in the hospital, usually over a period of 2 to 3 weeks. It may also be given in sessions at a doctor's office, at a psoriasis daycare centre, or at home. A session usually lasts 8 hours, and 1 to 6 sessions a week are needed.

The Ingram regimen combines bathing with a coal tar product, applying dithranol cream, and getting UVB light therapy. The treatment takes about 3 weeks and can be done in the hospital or in a day treatment program.

How It Works

Coal tar makes psoriasis plaques thinner and less red.

Coal tar helps improve the effectiveness of other treatments, such as ultraviolet light or corticosteroid creams.

Why It Is Used

Coal tar products are used to treat mild or severe psoriasis plaque that affects small areas of the skin.

When psoriasis covers more of the body, tar may be used together with UVB light therapy.

How Well It Works

Tars have been used to treat psoriasis for many years, but studies disagree about how well they work.1

In general, tar together with UVB light is thought to work better than tar alone.

Side Effects

Coal tar preparations are generally thought to be safe. There have been some concerns of cancer-causing chemicals in coal tar. But the U.S. Food and Drug Administration (FDA) reports that the chemical concentrations in over-the-counter coal tar are at safe levels. Use coal tar carefully when the skin rash is inflamed or is near the eyes or in skin folds.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Coal tar therapies are messy and time-consuming.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.



  1. Naldi L, Rzany B (2009). Psoriasis (chronic plaque), search date August 2007. Online version of BMJ Clinical Evidence: http://www.clinicalevidence.com.


By Healthwise Staff
Primary Medical Reviewer Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer Alexander H. Murray, MD, FRCPC - Dermatology
Last Revised March 29, 2010

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