Black Root

Reviewed on 6/11/2021
Other Name(s):

Beaumont Root, Bowman's Root, Culveris Root, Culvers, Culver's Physic, Culver's Root, Hini, Leptandra, Leptandra virginica, Oxadoddy, Physic Root, Purple Leptandra, Racine Noire, Tall Speedwell, Tall Veronica, Veronica virginica, Veronica Virginica Root, Veronicastrum virginicum, Véronicastre de Virginie, Véronique de Virginie, Whorlywort.


Black root is a plant. It grows in the US and Canada and has a bitter and nauseating taste. People use the underground stem (rhizome) and the root as medicine.

Black root is used for ongoing constipation and disorders of the liver and gallbladder. It is also used to cause vomiting.

How does it work?

Black root might increase bile flow from the gallbladder into the intestine.


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Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

  • Constipation.
  • Liver problems.
  • Gallbladder problems.
  • Causing vomiting.
  • Other conditions.
More evidence is needed to rate the effectiveness of black root for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).

Side Effects

There isn't enough information to know if taking black root is safe.

However, there have been reports of stomach pain or cramps, changes in stool color or odor, drowsiness, headache, nausea, and vomiting after taking black root. Large doses have been linked to reports of liver damage.


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Special Precautions & Warnings

Pregnancy and breast-feeding: It might be UNSAFE to take the fresh root by mouth. There is a concern that it might cause miscarriages and birth defects, but this hasn't been proven so far. Stay safe and don't take black root if you are pregnant.

It's also best to avoid black root if you are breast-feeding. Not enough is known about how it might affect the nursing infant.

Gallbladder problems such as gallstones or a blocked bile duct: Don't take black root if you have gallbladder problems. It might make your condition worse.

Inflammation of the stomach or intestines, such as colitis or Crohn's disease: Black root can irritate the digestive tract, cause vomiting, and act like a laxative. All of these effects might be harmful if you have colitis, Crohn's disease, or a similar condition. Don't take black root if you have one of these disorders.

Hemorrhoids: Don't use black root if you have hemorrhoids. It can act like a laxative and make hemorrhoids more bothersome.

Menstruation: Don't take black root if you are having your period. It can act like a laxative and add to discomfort.


Digoxin (Lanoxin)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Black root is high in fiber. Fiber can decrease the absorption and decrease the effectiveness of digoxin (Lanoxin). As a general rule, any medications taken by mouth should be taken one hour before or four hours after black root to prevent this interaction.

Warfarin (Coumadin)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Black root can work as a laxative. In some people black root can cause diarrhea. Diarrhea can increase the effects of warfarin and increase the risk of bleeding. If you take warfarin do not to take excessive amounts of black root.

Water pills (Diuretic drugs)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Black root is a laxative. Some laxatives can decrease potassium in the body. "Water pills" can also decrease potassium in the body. Taking black root along with "water pills" might decrease potassium in the body too much.

Some "water pills" that can decrease potassium include chlorothiazide (Diuril), chlorthalidone (Thalitone), furosemide (Lasix), hydrochlorothiazide (HCTZ, HydroDiuril, Microzide), and others.


The appropriate dose of black root depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for black root. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

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Health Solutions From Our Sponsors


Fetrow CW, Avila JR. Professional's Handbook of Complementary & Alternative Medicines. 1st ed. Springhouse, PA: Springhouse Corp., 1999.

Lust J. The herb book. New York, NY: Bantam Books, 1999.

Williamson EM, Evans FJ, eds. Potter's New Cyclopaedia of Botanical Drugs and Preparations. Essex, England: CW Daniel Company Ltd., 1998.

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