What Is Isatis Tinctoria Root Extract?

What Is Isatis Tinctoria Root Extract?

This is part of our ongoing series helping consumers better understand chemicals, chemistry, and product formulations. We translate the science, bust the myths, and give you an honest assessment, so you can make informed choices for your family!


Isatis Tinctoria Root Extract (aka dyer’s woad and glastum)

What it is:

Isatis tinctoria is a flowering plant from the mustard family that grows about 2-4 feet tall and has a root system with a thick taproot that can plunge more than 5 feet in depth. To create the commercial product, the roots are soaked in alcohol to promote the release of the beneficial materials. Then the alcohol is vacuumed out, the remaining liquid is filtered to eliminate impurities, and it’s dried to create an extract powder. (Historical texts cite this method, but back in the day, people soaked the herbs or flowers in wine!)

While it’s native to Europe and Asia, if you live in Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Utah, Washington, or Wyoming, you’ve likely seen it growing in roadside ditches and open rangelands – especially in late spring when it’s bright yellow flowers are in bloom. Isatis tinctoria was introduced to North America when some of the first settlers from Europe came over in the 1600’s. Now, it can be found across the continent, but it’s especially pervasive in the states listed above, where it’s considered a noxious weed.

What it does:

Isatis tinctoria is most commonly known as ‘dyer’s woad’ because the leaves can be used to make blue dye. The Egyptian used it to dye mummy’s wrapping cloth; it’s been found on pottery dating back to the Iron Age; and some historical accounts say it was used by ancient warriors as body paint! The roots have been used in traditional Chinese medicine for centuries due to its impressive health promoting qualities, including:

  • Treating fever, sore throat, tonsillitis, the common cold, flu, respiratory ailments, hepatitis, chickenpox, herpes, mumps, and some skin infections;
  • Warding off severe acute respiratory syndrome (SARS);
  • Stimulating the immune system;
  • Acting as an antibacterial, antiviral, and anti-inflammatory agent;
  • Relieving bacterial conjunctivitis; and,
  • Fighting cancer. (The plant has unusually high levels of the same cancer-fighting compound found in broccoli; and preliminary studies show it kills human liver cancer and leukemia cell lines.)

Somebody give that root a cape because it seems to be a superhero!

(Word to the wise: Even though this root extract has significant health promoting potential, always consult a health professional when considering alternative medicines for treating serious illness or disease.)

Why we use it:

Why not use it? When we were developing the formula for our Kid’s Immunity Boost, it was obvious that this VIP (Very Important Plant) had to be included. While many herbal remedies have been used for centuries, there’s very little (relatively speaking) scientific research to confirm efficacy. Isatis tinctoria has actually been studied quite a bit - both in vitro (in the lab) and in vivo (in real life). Many of the health benefits listed above are based on preliminary studies and require more testing, but the immune boosting powers of this plant are shown to be natural, non-toxic, and effective – our favorite!

Why we’re featuring it today:

There are two things parents should be aware of before using products with isatis tinctoria.

  1. This plant contains chemicals similar to chemicals found in aspirin, so it can trigger an allergic reaction or asthma attack in people with aspirin allergies.
  2. According to traditional Chinese medicine recommendations, children should avoid large doses and long-term use of isatis tinctoria. While some children’s products contain over 800 mg of isatis tinctoria root extract and are sometimes taken several times a day, ours has only 120 mg – erring on the side of safety, while still being effective.

As always, we recommend you consult your healthcare provider before using any health and wellness product.

Still have questions about isatis tinctoria root extract? Let us know in the comments!


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We aim to provide you with the most honest and credible information possible. This article was reviewed for accuracy by The Honest Team and was written based on trusted sources that are linked at the bottom of the article.