Hound's Tongue

Last Editorial Review: 6/11/2021
Other Name(s):

Bizniega, Cinoglosa, Cynoglosse, Cynoglosse Officinale, Cynoglossi Herba, Cynoglossi Radix, Cynoglossum officinale, Dog-Bur, Dog's Tongue, Fleur Gitane, Gypsy Flower, Langue-de-Chien, Langue de Chien, Lengua de Perro, Oreja de Liebre, Sheep-Lice, Viniebla, Woolmat.

Overview

Hound's tongue is a plant. The leaf and root are used to make medicine.

Despite serious safety concerns, people take hound's tongue for cough, pain, infections, skin diseases, and bronchitis, as well as diarrhea and other digestion problems.

Some people apply hound's tongue directly to the skin for pain, muscle pain, nerve pain, trauma, wounds, and scars.

How does it work?

There isn't enough information available to know how hound's tongue might work as a medicine.

QUESTION

Next to red peppers, you can get the most vitamin C from ________________. See Answer

Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

  • Diarrhea and other digestion problems.
  • Skin diseases.
  • Bronchitis.
  • Cough.
  • Pain, when taken by mouth or applied to the skin.
  • Wounds, when applied to the skin.
  • Other conditions.
More evidence is needed to rate the effectiveness of hound's tongue 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

Hound's tongue is UNSAFE and poisonous. There's a lot of concern about using hound's tongue as medicine, because it contains chemicals called hepatotoxic pyrrolizidine alkaloids (PAs), which may block blood flow in the veins and cause liver damage. Hepatotoxic PAs might also cause cancer and birth defects. Hound's tongue preparations that are not certified and labeled “hepatotoxic PA-free” are considered UNSAFE.

It's also UNSAFE to apply hound's tongue to broken skin. The dangerous chemicals in hound's tongue can be absorbed quickly through broken skin and can lead to dangerous body-wide toxicity. Steer clear of skin products that aren't certified and labeled “hepatotoxic PA-free.” There isn't enough information to know if it's safe to apply certified hepatotoxic PA-free hound's tongue to unbroken skin. It's best to avoid use.

SLIDESHOW

Vitamin D Deficiency: How Much Vitamin D Is Enough? See Slideshow

Special Precautions & Warnings

Hound's tongue isn't safe for anyone to use. Some people may be extra sensitive to the toxic effects and should be particularly careful to avoid use.

Pregnancy and breast-feeding: It's UNSAFE to use hound's tongue preparations that might contain hepatotoxic PAs during pregnancy. These products might cause birth defects and liver damage.

It's also UNSAFE to use hound's tongue preparations that might contain hepatotoxic PAs if you are breast-feeding. These chemicals can pass into breast-milk and might harm the nursing infant.

It's not known whether products that are certified hepatotoxic PA-free are safe to use during pregnancy or breast-feeding. Stay in the safe side and avoid using any hound's tongue preparation if you are pregnant or breast-feeding.

Liver disease: There is concern that the hepatotoxic PAs in hound's tongue might make liver disease worse.

Interactions


Medications that increase break down of other medications by the liver (Cytochrome P450 3A4 (CYP3A4) inducers)Interaction Rating: Moderate Be cautious with this combination.Talk with your health provider.

Hound's tongue is broken down by the liver. Some chemicals that form when the liver breaks down hound's tongue can be harmful. Medications that cause the liver to break down hound's tongue might enhance the toxic effects of chemicals contained in hound's tongue.

Some of these medicines include carbamazepine (Tegretol), phenobarbital, phenytoin (Dilantin), rifampin, rifabutin (Mycobutin), and others.

Dosing

The appropriate dose of hound's tongue 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 hound's tongue. 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.

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

References

Chojkier M. Hepatic sinusoidal-obstruction syndrome: toxicity of pyrrolizidine alkaloids. J Hepatol 2003;39:437-46. View abstract.

Food and Drug Administration. FDA Advises Dietary Supplement Manufacturers to Remove Comfrey Products From the Market. July 6, 2001. Available at: http://www.cfsan.fda.gov/~dms/dspltr06.html.

Klepser TB, Klepser ME. Unsafe and potentially safe herbal therapies. Am J Health Syst Pharm 1999;56:125-38. View abstract.

Roeder E. Medicinal plants in Europe containing pyrrolizidine alkaloids. Pharmazie 1995;50:83-98.

Wang YP, Yan J, Fu PP, Chou MW. Human liver microsomal reduction of pyrrolizidine alkaloid N-oxides to form the corresponding carcinogenic parent alkaloid. Toxicol Lett 2005;155:411-20. View abstract.

WHO working group. Pyrrolizidine alkaloids. Environmental Health Criteria, 80. WHO: Geneva, 1988.