Coal tar shampoos are formulated to treat the symptoms of scalp psoriasis, dermatitis, and dandruff. Brands extensively advertise their percentage of coal tar, the primary active ingredient in these shampoos. It might be tempting to grab whichever bottle claims the highest percentage of coal tar printed the biggest on the front label. Unfortunately, it’s not that simple. Here are five tips to put you in the know about coal tar, advertising claims, and concentrated USP.

1. Understand how coal tar is used.

When talking about active ingredients for psoriasis shampoos, coal tar is the active ingredient in many scalp shampoos. It’s been used for more than 100 years to safely mitigate itching and flaking caused by scalp psoriasis and dermatitis. You will see product labels advertising an ingredient make up anywhere from 0.5 to 5 percent.


2. Interpret the concentrated USP.

Coal tar topical solution is available only as a 20 percent (20%) solution. So, MG217 Coal Tar Shampoo uses 15 percent (15%) of USP Coal Tar Topical Solution to produce a three percent (3%) coal tar shampoo. In other words, you need to pay attention to a percentage of a percentage.


3. Know how much active ingredient you need.

A stronger dose is better. This is particularly true since coal tar shampoos are a wash-off product, so the coal tar has only a short time to be in contact with the scalp to impact the psoriatic skin.”


4. Compare apples to apples or coal tar to coal tar.

Some products also advertise proprietary ingredients with brand names that may sound similar to coal tar. These branded ingredients are also listed by a percentage. Pay attention to the coal tar concentration itself when comparing products with branded ingredients. Be sure to compare equivalent coal tar percentage cited on the package and not extracts or branded ingredients. The amount of coal tar in the product will be listed under the drug facts.


5. Look for a seal of approval.

You should also watch for products that are recognized by the National Psoriasis Foundation, which is the foremost expert and national advocate for psoriasis.