Is Coal Tar Shampoo Safe for Long-Term Use? What the Research Says

If you have been using coal tar shampoo for scalp psoriasis — or considering it — you have probably wondered whether it is safe to use long term. The concern is understandable. Coal tar has industrial uses, there are cancer warnings on some products in California, and the smell alone can make it feel like something powerful enough to cause harm. This article explains what the evidence actually says, which precautions genuinely matter, and who should be cautious.

Where the Safety Concern Comes From

Coal tar is a byproduct of coal processing, and in industrial forms — used in road paving, roofing, and manufacturing — prolonged occupational exposure has been associated with elevated cancer risk. This is where the concern originates. Some animal studies using extremely large quantities of coal tar also showed increased cancer risk.

The key distinction is concentration and context. Industrial coal tar exposure involves vastly higher concentrations than what is present in OTC psoriasis shampoos, applied to a small area of skin for a few minutes at a time. The FDA and AAD have both reviewed the evidence and concluded that OTC products containing 0.5% to 5% coal tar do not carry meaningful cancer risk when used as directed for psoriasis treatment.

California requires cancer warning labels on OTC coal tar products containing more than 0.5% coal tar. This is a state regulation — not an FDA finding — and reflects California's precautionary labeling standards rather than evidence of risk at therapeutic concentrations.

What the Evidence Actually Shows

The FDA Position

The FDA has determined that OTC coal tar products with concentrations between 0.5% and 5% are safe and effective for psoriasis, seborrheic dermatitis, and dandruff. This determination has been reviewed and maintained over decades of use.

The AAD Position

The American Academy of Dermatology considers coal tar safe for long-term use and includes it in its official treatment guidelines for psoriasis. The AAD specifically notes that there is no scientific evidence that coal tar in OTC psoriasis products causes cancer, and that the industrial cancer risk does not apply to therapeutic use.

Over 100 Years of Clinical Use

Coal tar has been used in dermatology since the early 1900s. The Goeckerman regimen — combining coal tar with UV light therapy — has been used to treat severe psoriasis since the 1920s and remains in clinical use today. A treatment with a century of clinical history and no documented pattern of harm in therapeutic use has a meaningful safety record that newer treatments have not yet accumulated.

Precautions That Genuinely Matter

While coal tar is considered safe for long-term use, several precautions are important and should be followed consistently:

Sun Exposure — The Most Important Precaution

Coal tar increases the skin's sensitivity to ultraviolet light. This is the single most clinically significant precaution. Always wash coal tar shampoo out completely before sun exposure. Do not leave coal tar products on the scalp and go outdoors without rinsing. This applies whether you are using a shampoo, pomade, or any other coal tar topical.

Avoid the Eye Area

Coal tar should not come into contact with the eyes. If contact occurs, rinse thoroughly with water. When applying coal tar shampoo, keep the lather focused on the scalp rather than allowing it to run down the face.

Pregnancy and Breastfeeding

Pregnant or breastfeeding women may want to use an alternative treatment. The evidence on coal tar safety in pregnancy is limited, and most dermatologists recommend caution as a precautionary measure during this period.

Patch Testing for New Users

Some people have skin sensitivity to coal tar. If you are using it for the first time, test a small area before full application. Discontinue use if you experience significant burning, swelling, or rash beyond normal skin response.

Common Questions Answered

Long-Term Use With Nopsor

Nopsor Shampoo contains 2.2% coal tar — within the FDA-approved range for OTC psoriasis products — combined with salicylic acid and a blend of 8 medicinal herbs. The formula was developed by José Luis Aguilar Sánchez, who used it on his own scalp psoriasis for over 25 years. Ernesto Aguilar, Nopsor USA CEO, has used the pomade for maintenance since achieving remission from palmoplantar psoriasis.

Long-term use of Nopsor follows the same safety profile as other coal tar products at therapeutic concentrations — effective, well-tolerated, and supported by decades of clinical evidence. The key precautions are consistent: wash out before sun exposure, avoid the eye area, and monitor your skin's response.