Coal tar has been used for years to treat psoriasis and seborrheic dermatitis. This industrial by-product is a keratolytic agent, meaning it reduces the growth rate of skin cells and softens keratin. Lab studies have found that even low concentrations of coal tar in products can inhibit Malassezia growth.
However, coal tar shampoos are not as effective as other medicated anti-dandruff shampoos. You’re also more likely to get side effects from coal tar products. And the icing on the cake? Coal tar is now banned in the European Union for being a carcinogen (cancer-causing compound).
Let’s take a deep dive:
What is coal tar?
Coal tar is a thick, dark liquid that is a by-product of the production of coke and coal gas from coal.
In industrial settings, coal tar is often used as a railroad tie preservative and to resurface roads.
People started using coal tar for medical purposes as early as the 1800s. Now it’s used in many products and preparations, including topical skin treatments for proriasis and seborrheic dermatitis (SD).
Coal tar is made up of approximately 10,000 chemicals, of which only about 50% have been identified. Some of these chemicals include benzene, toluene, xylene, and p-xylene.
Anyone up for some road goop?
What does coal tar do for the skin?
Coal tar is a keratolytic agent, meaning it can reduce the growth rate of skin cells and soften keratin.
Coal tar is antifungal, anti-inflammatory and anti-itch. These properties make it a treatment option for psoriasis, seborrheic dermatitis and even dandruff.
You can even use coal tar to kill head lice.
Is coal tar an antifungal?
Coal tar is so toxic it kills everything on your skin. Including your skin.
Biased opinion aside, lab studies have found that coal tar, even in concentrations as low as 0.5%, can inhibit Malassezia.
Is coal tar good for seborrheic dermatitis?
Coal tar has been used for centuries as a topical treatment for various skin conditions, including seborrheic dermatitis. As you can see, the evidence shows that coal tar is actually an effective treatment for SD, but at what cost?
The use of coal tar on the face has fallen out of favor over the years as other better and safer anti-seborrhea products became available. After all, who wants to put road muck on their skin if they don’t have to?
The only coal tar products I see being recommended now are coal tar shampoos like Neutrogena T/Gel Shampoo for scalp seborrheic dermatitis or severe dandruff. Even then, other medicated shampoos have been shown to be more effective.
Is coal tar better than ketoconazole?
Two large double-blind trials compared 4% coal tar, 4% coal tar and 1% ciclopirox olamine, and 2% ketoconazole shampoo. They found that coal tar shampoo was less effective at treating scalp seborrheic dermatitis compared to coal tar/ciclopirox or ketoconazole shampoo.
Coal tar vs salicylic acid shampoos
A smaller randomized double-blind study compared a non-tar shampoo (2% salicylic acid, 0.75% piroctone olamine, 0.5% elubiol) and 0.5% coal tar shampoo. Not surprisingly, they found that the non-tar shampoo was better than the coal tar shampoo at controlling Malassezia growth.
Side effects of coal tar products
Coal tar products can cause skin irritation, dryness, scaling, redness, and peeling. Some people also experience allergic reactions to coal tar products.
Never apply coal tar to inflammed, broken or infected skin. You definitely don’t want coal tar absorbing through your blood stream. Unfortunately, dandruff sufferers scratch, no matter how discreetly, and this causes micro-tears in the scalp.
WHO also recommends that you avoid direct sunlight for at least 24 hours after treatment because coal tar can make your skin more photosensitive.
Is coal tar cancerous?
Peopl who worked with coal tar for the long term was found to be at much higher risk of cancer. However, there is no conclusive evidence that applying coal tar to a limited area of your skin or scalp increases your risk of cancer. In fact, an American specialist panel found that using coal tar in ‘appropriate concentrations’ (small amounts) did not have any cancer-causing effect on the user.
However, the European Union banned coal tar cosmetic and skincare products last year, labeling it a carcinogen (cancer-causing product).
To wrap up
Coal tar products, including shampoos, may be somewhat effective for seborrheic dermatitis but are not worth the risks to your health. There are many anti-dandruff and anti-seborrhea products that are much safer to use.
Further reading:The 8 best scalp oils for seborrheic dermatitis and dandruff