- Tsuga canadensis
- Alpha-Phellandrene, alpha-pinene, beta-phellandrene, beta-pinene, bornyl acetate, camphene, Canada pitch, Canadian hemlock, catechin, epicatechin, flavan-3-ols, flavanols, hemlock bark, hemlock gum, hemlock spruce, Hemlocktanne, limonene, myrcene, Pinaceae (family), Pinus bark, Pinus extract, proanthocyanidins, Pruche de l’est, tannin, terpinolene, tricyclene, Tsuga canadensis Carriere, Tsuga Canadensis, L.
- Eastern hemlock contains tannins (organic compounds), which are responsible for some of its medicinal properties. The bark has astringent properties, and the leaves contain significant amounts of vitamin C.
- Traditionally, Eastern hemlock was used to treat digestive disorders, mouth/throat disorders, and diarrhea.
- Although the Eastern hemlock is primarily used for lumber today, Native Americans used the tree’s cambium (the tissue in a plant that produces new cells) in breads, soups and pemmican (dried, pounded meat mixed with fat and berries). Early settlers also used the tree in dying wool and tanning leather.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
*Key to grades:
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Adults (over 18 years old)
- There is no proven safe or effective dose for Eastern hemlock in adults, and use is not recommended.
Children (under 18 years old)
- There is no proven safe or effective dose for Eastern hemlock in children, and use is not recommended.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
- Avoid in individuals with a known allergy or hypersensitivity to Eastern hemlock.
Side Effects and Warnings
- Little information is available on the adverse effects of Eastern hemlock. However, due to its high tannin content, Eastern hemlock may cause gastrointestinal upset, necrosis (tissue death) of the liver or kidney damage. Eastern hemlock is possibly unsafe when used in patients with impaired liver or kidney function.
Pregnancy and Breastfeeding
- Eastern hemlock is not recommended in pregnant or breastfeeding women due to a lack of available scientific evidence.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Interactions with Drugs
- Theoretically, concomitant ingestion may cause precipitation of some drugs due to the high tannin content of Eastern hemlock. Consult with a qualified healthcare professional, including a pharmacist, to check for any interactions.
Interactions with Herbs and Dietary Supplements
- Theoretically, concomitant ingestion may cause precipitation of some herbs due to the high tannin content of Eastern hemlock. Consult with a qualified healthcare professional, including a pharmacist, to check for any interactions.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
- This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration ().
- Broeckling CD, Salom SM. Volatile emissions of eastern hemlock, Tsuga canadensis, and the influence of hemlock woolly adelgid. Phytochemistry 2003;62(2):175-180.
- Feucht W, Treutter D, Polster J. Flavanol binding of nuclei from tree species. Plant Cell Rep. 2004;22(6):430-436.
- Forest Service. Eastern Hemlock. American Woods–FS-239 1970.
- Mitchell, J. C. Patch test results – screening set and plants. Contact Dermatitis Newsletter 1970;8:177.
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.