Alkanet root is the dried root of Alkanna tinctoria, a plant in the borage family that has been used for thousands of years as a natural colorant for textiles, food, and cosmetics. The root contains pigments that produce deep red, purple, and blue hues depending on how they’re extracted and what pH environment they’re in. Today it’s most commonly found in soapmaking and cosmetic crafting, though it carries some important safety considerations.
The Plant and Its Pigments
Alkanna tinctoria is a low-growing, hairy perennial native to the Mediterranean region. The plant itself is unremarkable, with small blue flowers, but the root is where the value lies. When you cut or peel the root, you’ll find a dark reddish-brown bark that contains the coloring compounds.
The primary pigment is alkannin, a naturally occurring compound in a class called naphthoquinones. Alkannin dissolves readily in oils and fats but barely dissolves in water, which is why alkanet root is almost always infused in oil rather than steeped like a tea. This oil solubility is what makes it so useful in balms, salves, and soap. The color alkannin produces shifts with pH: in acidic conditions it leans red, while in alkaline conditions (like the lye used in soapmaking) it turns purple or blue.
How Alkanet Root Is Used Today
The most popular modern use for alkanet root is as a natural colorant in cold process soap. Soapmakers typically infuse the dried, chopped root in a carrier oil for several weeks, then strain out the root material and use the deeply pigmented oil in their recipe. A common ratio is 1 to 3 teaspoons of root powder per pound of soapmaking oils. Because cold process soap is highly alkaline, the infused oil usually produces shades of purple, lavender, or blue-gray in the finished bar.
Beyond soap, crafters use alkanet-infused oil in lip balms, lotions, and wood stains. Historically, it was also used to color fabrics, wines, and food products. The FDA once allowed alkanet as a provisional food colorant in the United States, but it was delisted in 1964 and is no longer approved for food use.
Wound Healing and Antimicrobial Properties
Alkannin and its closely related mirror-image compound, shikonin, have drawn research attention for their biological activity. Lab and animal studies have established these compounds as having anti-inflammatory, antimicrobial, antioxidant, and cell-growth-promoting properties. In one controlled veterinary study, wounds treated with an alkannin/shikonin ointment showed significantly more new blood vessel formation by day 4, greater collagen production through day 20, and thicker new skin tissue by day 11 compared to untreated wounds. The treated wounds also had less tissue death and less purulent discharge overall.
These results are consistent with earlier research showing that alkannin and shikonin stimulate several growth factors involved in tissue repair, including those that drive new blood vessel formation and skin cell proliferation. Reduction of swelling has been reported in both animal and human studies. That said, this research is largely preclinical. The compounds show genuine biological activity, but standardized wound care products based on alkanet root are not widely available or regulated.
Safety Concerns With Alkanet Root
Alkanet root contains pyrrolizidine alkaloids (PAs), a class of compounds found in many plants in the borage family. At least three distinct PAs have been isolated from Alkanna tinctoria. These compounds are well documented to cause liver damage, and they can also harm the lungs, nervous system, and DNA. PA toxicity occurs in both humans and animals, often through contaminated teas, honey, or herbal preparations taken by mouth.
Because of these compounds, taking alkanet root internally is considered unsafe. The root should not be consumed as a tea, supplement, or food additive. Topical use also raises concerns. PAs can be absorbed quickly through broken skin and cause systemic toxicity. Even on intact skin, there isn’t enough safety data to confirm that topical application is risk-free. Some manufacturers sell products labeled “hepatotoxic PA-free,” meaning they’ve attempted to remove the liver-damaging alkaloids, but there’s insufficient evidence to confirm these purified versions are safe either.
For soapmakers, the risk profile is different. During the saponification process, the high pH and chemical reactions may degrade some of these compounds, and the finished soap is a rinse-off product with brief skin contact. Most soapmakers treat alkanet as a colorant used in very small quantities in a wash-off product, which is a meaningfully different exposure than applying an alkanet-infused oil directly to skin as a leave-on balm.
Alkanet vs. Comfrey and Other Borage Relatives
Alkanet root is sometimes confused with comfrey root, another borage family plant with PA concerns. They are different plants with different active compounds: comfrey contains allantoin and is traditionally associated with bone and tissue healing, while alkanet’s signature compounds are the naphthoquinone pigments alkannin and shikonin. Both carry PA risks, but they aren’t interchangeable.
You may also see “alkanet” sold alongside or confused with “henna” or “anchusa.” True alkanet (Alkanna tinctoria) is distinct from bugloss (Anchusa officinalis), which is sometimes called “common alkanet” but lacks the same concentrated root pigment. When purchasing alkanet root for crafting, look for the botanical name Alkanna tinctoria to make sure you’re getting the correct plant.