Coal Tar for Psoriasis

Century-old remedy remains a safe and viable treatment

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Coal tar is a byproduct of coal processing that has been used for more than a century to treat skin problems. Today, coal tar for plaque psoriasis is considered an effective, safe, and inexpensive topical treatment. Available in different strengths and formulations, coal tar is included on the World Health Organization (WHO)'s List of Essential Medicines. It has also been approved by the U.S. Food and Drug Administration (FDA) under the classification "generally recognized as safe and effective" (GRASE).

Coal tar was first discovered around 1665 and used for medical purposes as early as the 1800s.

Dermatology consultation
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Coal tar belongs to a class of drugs called keratoplastics, which also include benzoyl peroxide, tretinoin, and salicylic acid. Coal tar works against psoriasis by directly interfering with the synthesis of DNA in the skin. This action can help slow the abnormal buildup of skin cells and decrease the size of psoriatic plaques.

Coal tar also promotes the shedding of dead cells from the top layer of skin, known as the stratum corneum. This can help reduce dandruff as well as itchiness and scaling. Coal tar is especially useful in treating scalp psoriasis and hard-to-treat palmoplantar psoriasis (psoriasis of the palms and soles).

A 2014 study in the Indian Journal of Dermatology reported that a 12-week course of coal tar paired with salicylic acid was just as effective in relieving plaque psoriasis as the prescription drugs calcipotriol and betamethasone.

Side Effects

Over-the-counter (OTC) coal tar products are considered safe if used in concentrations between 0.5% and 5%. More potent coal tar is more likely to cause irritation and dryness. The side effects of coal tar psoriasis products can be minimized by applying moisturizer before the coal tar preparation.

Coal tar can make the skin extra-sensitive to sunlight, often for up to 24 hours after application. To avoid sunburn, wash your skin thoroughly after a coal tar treatment and apply a high-SPF sunscreen if you plan to be outdoors.

Coal tar can also stain clothes, towels, bedding, and even light-colored hair. It often helps to apply the preparation in the shower and to wash and rinse it off thoroughly afterward. Any discoloration of hair will usually return to normal after a few shampoos. Liquor carbonis distillate (LCD) coal tar products are less likely to stain light or color-processed hair.

While certain compounds in coal tar are considered carcinogenic (cancer-causing), the level in a 0.5% to 5% preparation is thought to be negligible.

The National Psoriasis Foundation says there is no scientific evidence that coal tar is carcinogenic in the low concentrations found in psoriasis products.

There are also no known drug interactions associated with coal tar. Allergic reactions are rare, but may occur. If you are prone to allergies, patch test the product on a small area of skin and wait 24 hours to see if a rash develops.

Call 911 or seek emergency care if you experience hives, difficulty breathing, chest tightness, irregular heartbeats, dizziness, or the swelling of the face, tongue, or throat after using coal tar.

Products and Formulations

Coal tar is found in a plethora of OTC products, including coal tar creams, gels, and bath additives. Coal tar shampoos are also available for scalp psoriasis, Compound pharmacists can mix crude coal tar (which has a black, paste-like texture) or an alcohol-based coal tar solution with all sorts of bases, including steroid creams and ointments.

Coal tar products intended for baths or foot soaks should be mixed thoroughly and used for around 10 to 15 minutes. Take extra care when using coal tar in bathtubs or showers as it can make surfaces extremely slippery.

Coal tar is intended for use external only. Take special care when applying coal tar to face; avoid getting any into the eyes, nostrils, and mouth. The same applies to the rectum, vagina, or urethra. If you accidentally get coal tar in the eyes or other delicate tissues, rinse thoroughly with cool water for 15 minutes.

Leave coal tar on psoriasis plaques for at least two hours. Because coal tar keeps working for up to 24-hours, you should avoid exposure to the sun while coal tar is on your skin.

Coal tar preparations should never be applied to inflamed, broken, or infected skin. Doing so may cause pain and trigger a psoriatic flare.

Coal tar is sometimes used with phototherapy to sensitize the skin to ultraviolet (UV) radiation. This should only be performed by a dermatologist who is trained to deliver the correct dose using specialized phototherapy equipment. Never use a tanning bed or lamp to treat psoriasis as it is more likely to cause skin damage or trigger a flare.

For safety, coal tar should only be used in children under the direction of a dermatologist.


The dosage varies by the strength of the preparation. To avoid side effects, follow the instructions on the product label or ask your pharmacist for advice. Topical coal tar products should be massaged into the skin and allowed to dry.

What to Look For

There are literally hundreds of different coal tar preparations found on drugstore shelves and online. When choosing a product, opt for one that has undergone testing with an independent certifying body like the U.S. Pharmacopeia (USP), NSF International, or ConsumerLab. In this way, you will know for sure that the product contains the ingredients listed on the label in the declared potency level.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. World Health Organization. Coal tar. Geneva, Switzerland.

  2. Ahmed A, Danish M. Coal tar burn in emergency room. Int J Advances Med Sci. 2(1):1-5.

  3. Sekhon S, Jeon C, Nakamura M, et al. Review of the mechanism of action of coal tar in psoriasis. J Dermatolog Treat. 29(3):230-232. doi:10.1080/09546634.2017.1369494

  4. Khandpur S, Sahni K. An open-label prospective randomized trial to compare the efficacy of coal tar-salicylic acid ointment versus calcipotriol/betamethasone dipropionate ointment in the treatment of limited chronic plaque psoriasis. Indian J Dermatol. 59(6):579-83. doi:10.4103/0019-5154.143523

  5. U.S. Food and Drug Administration. Code of Federal Regulations, Title 21, Volume 5, Subchapter D -- drugs for human use. Part 358, miscellaneous external drug products for over-the-counter human use. Subpart H--drug products for the control of dandruff, seborrheic dermatitis, and psoriasis.

  6. Cleveland Clinic. Coal Tar skin cream, lotion, or gel.

  7. Roelofzen JH, Aben KK, Oldenhof UT, et al. No increased risk of cancer after coal tar treatment in patients with psoriasis or eczema. J Invest Dermatol. 130(4):953-961. doi:10.1038/jid.2009.389

  8. National Psoriasis Foundation. Over-the-counter topicals.

  9. Cleveland Clinic. Coal tar bath solution.

  10. Elmets CA, Lim HW, Stoff B, et al. Joint American Academy of Dermatology-National Psoriasis Foundation guidelines of care for the management and treatment of psoriasis with phototherapy. J Am Acad Dermatol. 81(3):775-804. doi:10.1016/j.jaad.2019.04.042

  11. National Psoriasis Foundation. Tanning beds no substitute for phototherapy for psoriasis.

Additional Reading

By Dean Goodless, MD
 Dean R. Goodless, MD, is a board-certified dermatologist specializing in psoriasis.