Tar soap is a natural remedy thought to have powerful antiseptic abilities. It’s often used to treat skin conditions like psoriasis and eczema.

Tar soap is sometimes recommended to relieve psoriasis symptoms, like itching, inflammation, and scaling. The two types of tar soap used to treat psoriasis are pine tar soap and coal tar soap.

Pine tar soap is made from pine tree resins and has a strong pine scent. Some people still use it to treat psoriasis, but doctors who support tar soap as a treatment are more likely to recommend coal tar soap.

Coal tar is a distillation byproduct of coal processing. It’s made of thousands of compounds that may vary depending on preparation.

Read on for more information about these remedies.

The goal of psoriasis treatment is to slow the growth of skin cells, reduce inflammation and plaque formation, and remove scales.

Coal tar soap might help reduce scaling, itching, and inflammation. It has few side effects, although exactly how it works isn’t clear. According to the National Psoriasis Foundation, coal tar helps slow skin cell growth and improves skin’s appearance.

Coal tar treatments may be combined with other therapies, like topical corticosteroids or ultraviolet B light.

The Goeckerman regimen is a therapy that combines coal tar and ultraviolet light. It’s considered to be effective in relieving moderate to severe psoriasis symptoms. But the treatment isn’t right for everyone. Goeckerman requires daily sessions for up to 4 weeks and can be messy.

According to the American Academy of Dermatology (AAD), coal tar preparations are one remedy to treat psoriasis and atopic dermatitis. While it’s considered safe for long-term use, it may not be an appropriate treatment for everyone.

Coal tar soap is generally well-tolerated, but it may cause adverse side effects:

  • skin irritation or redness
  • rash
  • sensitivity to sunlight

The AAD warns to never use coal tar preparations on your gentials or rectum area unless a dermatologist specifically prescribes it for those areas.

In addition to being messy, coal tar soap has a strong, unpleasant odor and easily stains light-colored hair, clothes, and bedding.

Whether coal tar products cause cancer has been hotly debated. When studies suggested occupational exposure to coal tar may cause cancer, it raised concerns that topical use might be carcinogenic as well.

In 2010, a study published in the Journal of Investigative Dermatology seemed to put the debate to rest. The study didn’t observe an increased risk of cancer with the use of coal tar soap. It also noted that coal tar soap could be a safe treatment for psoriasis and eczema.

In addition to tar soap, other OTC treatments are available. Most OTC psoriasis treatments are used to moisturize and soothe skin, remove scales, and relieve itching. These include:

Occlusion, the process of covering an applied topical medication with plastic wrap, cellophane, or other covering, is sometimes used to increase a product’s effectiveness.

Talk with a doctor before using tar soap to treat psoriasis. They can give you tips on how much soap to use and how often.

If you experience the symptoms of an allergic reaction while using tar soap, seek medical help immediately. Those symptoms may include:

If the treated area becomes discolored, itchy, or irritated, or your symptoms worsen or don’t improve, call your doctor as soon as possible.

Tar soap might help ease some psoriasis symptoms. It can also be used as part of a combination treatment.

However, the soap may cause skin irritation, including an allergic reaction, so it’s a good idea to talk with your doctor before adding it to your treatment plan.