What is Indigo Naturalis?

Indigo Naturalis is the latin name for a family of botanicals that includes Baphicacanthus cusia, Polygonum tinctorium (Persicaria tinctoria), Isatis indigotica and Indigofera tinctoria. One of its most common forms is in a dried powder cultivated from the fermented leaves, blossoms and stems from these plants. Perhaps best known for its rich, highly pigmented dye used for textiles, Indigo Naturalis also has a long history of use in traditional Eastern medicine. Taken orally, it was primarily used to treat inflammation, especially in the stomach and digestive tract.

Indigo Naturalis gains its vibrant blue hue as a result of the fermentation and oxidization process. While most blue dyes are now synthetic, there are still a handful of Indigo farms in Tokushima, Japan and elsewhere that continue the traditional dyeing processes. After the plants blossom in the late summer, they are harvested and combined with water (and sometimes other ingredients) and covered with thick straw mats. Over the next few months, enzymes create a deep green liquid that turns blue with exposure to oxygen. Indigo Naturalis extract can be added to creams, ointments, oils, and more.

History of Indigo in Eastern Medicine

Indigo Naturalis has a long history in Japan and China. In Chinese herbal medicine, it is known as Qing Dai (青黛) and is often ingested to treat ailments including high fever, chronic myelogenous, child epilepsy, nose bleeds, sore throat, gum inflammation, tonsillitis, insect or snake bites, psoriasis and more.

During the Edo Period in Japan, Indigo was one of the most popular dyes for fabric. Samurai wore a layer of indigo-dyed cloth beneath their armor to heal wounds. The dye was also used to make traditional firefighter uniforms, as indigo blue was seen as a protective color. Indigo is so iconic to Japan that it is commonly referred to as “Samurai Blue” and “Japan Blue,” even today.

Indigo Naturalis for the Skin - a Rediscovery

Inspired by its historical use, Indigo Naturalis is still used by traditional herbalists to treat inflammation. It is sometimes taken as an oral supplement to compliment topical steroid treatments for skin disorders and for inflammatory conditions. Recently, interest in Indigo Naturalis to treat skin disorders has reemerged in Western medicine. Researchers are documenting the impressive results from using Indigo Naturalis as a topical treatment for skin disorders such as psoriasis and eczema. The long-term effects of Indigo Naturalis consumption is unknown, so the majority of the studies have focused on topical creams and ointments as alternatives to topical and oral steroids.

Steroids can cause many unwanted side effects and for many, have a systemic effect on the body. They can cause symptoms such as agitation, weight gain, swelling and thinning of skin. Certain steroids can also cause “moon face,” a medically recognized condition where the face becomes rounder as a result of fat-deposits that develop on its sides. These side effects can cause skin to undergo hyper-accelerated aging and unnatural changes in appearance. While steroids address skin irritation and regulate the body’s immune response, they can often leave the surface skin rough and dry. In children, steroids can have stronger side effects and may affect their growth. The side effects of steroids have encouraged researchers to look for safer treatment options for skin disorders, especially for those too young or who cannot tolerate them.

Recent Studies for Dermatitis and Related Skin Disorders

The active compound in Indigo, indirubin, has generated interest for its anti-inflammatory properties. The exact mechanism of how indirubin inhibits an imbalanced immune response is unknown, but shows promise for those with proliferative skin disorders. The other actives in Indigo, tyrptanthrin and isatin, also have anti-inflammatory, antibacterial, and antifungal effects on skin.

A study by Taiwanese researchers in 2008 treated patients with chronic psoriasis with a soothing ointment containing Indigo. After 12 weeks of the treatment, nearly 75 percent of the patients had cleared or nearly cleared their skin of psoriasis.

In a more recent 2012 study, patients with severe plaque psoriasis (where inflamed patches of skin are covered with white, painful scaling) were given Indigo ointments and showed significant improvement (74%) in only eight weeks. Another study concluded that indirubin, one of the actives in indigo naturalis, balanced the production of the outermost skin cells in patients with psoriasis, reducing their overproduction, which is symptomatic of this skin disorder. The Journal of the American Medical Association published research from other scientists whose studies found up to 81% improvement in severe dermatitis when skin was treated with natural indigo.


Indigo Naturalis is a promising topical ingredient as an alternative to systemic, steroid treatments for inflammatory skin disorders without adverse side effects. As formulas improve, creams with Indigo no longer leave skin blue, and disappear upon application. For those seeking a soothing ointment or cream that restores skin without thinning it, topical treatments with Indigo are worth incorporating into a regular skincare routine.


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  • http://dermatologytimes.modernmedicine.com/dermatology-times/news/indigo-naturalis
  • https://en.wikipedia.org/wiki/Persicaria_tinctoria
  • http://archderm.jamanetwork.com/article.aspx?articleid=420128&resultClick=3
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  • http://www.ncbi.nlm.nih.gov/pubmed/22721997
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