Cedar leaf oil (Thuja occidentalis)

While some complementary and alternative techniques have been studied scientifically, high-quality data regarding safety, effectiveness, and mechanism of action are limited or controversial for most therapies. Whenever possible, it is recommended that practitioners be licensed by a recognized professional organization that adheres to clearly published standards. In addition, before starting a new technique or engaging a practitioner, it is recommended that patients speak with their primary healthcare provider(s). Potential benefits, risks (including financial costs), and alternatives should be carefully considered. The below monograph is designed to provide historical background and an overview of clinically-oriented research, and neither advocates for or against the use of a particular therapy.

Related Terms

  • Abendländischer Lebensbaum (German), almindelig tuja (Danish), alpha-pinen, alpha-terpine, American arbor vitae, American White Cedar, Amerikanischer Lebensbaum (German), ameriški klek (Slovenian), Arbor Vitae, arborvitae, Austamerikansk tuja (Norwegian), benzylbutyrolactol, borneol, camphen, camphene, carvotanacetone, catechine, cedar of Lebanon, cedars of Lebanon, cedarwood, cedarwood oil, cèdre blanc (French), Cedrus, Coniferales, Cupressaceae (family), cypress, Eastern Arborvitae, Eastern white cedar, essential oils, evergreen, False White Cedar, fenchone, gallocatechine, glycoproteins, Hackmatack, harilik elupuu (Estonian), isothujone, Juniper, kaempferol, kaempherol, kaempherol-3-O-alpha-rhamnoside, kanadalainen elämänpuu (Finnish), Kanadalífviður (Icelandic), kanadantuija (Finnish), Lebensbaum (German), lignan, lignans ((-)-wikstromal (-)-matairesinol and benzylbutyrolactol)), limonene, livsträd (Swedish), matairesinol, mearnsitrin, Meijer medicated chest rub, myrcen, myricene, myricetine, myricitrin, northern white-cedar, nyugati tuja (Hungarian), oil of cedar leaf, oksident tuja (Norwegian), origanes, origanol, Østamerikansk tuja (Norwegian), p-coumaric acid, Pinaceae (family), Pinales, plicatic acid, polysaccharides, procyanidin B-3, prodelphinidin, quercetin, quercitrin, red cedar, sabines, swamp cedar, tannic acid, terpinolen, Thuj, Thuja, Thuja occidentalis L., thujone, thujone white cedar, thuya américain (French), thuya d’occident (French), thuya du Canada (French), thuya occidental (French), tree of life, tuia (Portuguese – Brazil), tuia occidentale (Italian), tuja (Norwegian, Swedish), tuya (Spanish), umbelliferone, vanlig tuja (Norwegian, Swedish), white cedar, wikstromal, yellow cedar, zerav západní (Czech), zywotnik zachodni (Polish).

  • Combination products: Esberitox® or SB-TOX, (containing a dry extract 4-9:1 blend of Baptisia tinctoria (wild indigo) root, Echinacea purpurea and pallida (coneflower) root, and Thuja occidentalis (white cedar) leaf).


  • Cedar leaf oil comes from the Thuja occidentalis tree. It has been used historically by different cultures to treat many conditions, including breathing disorders, cancers, headaches, heart ailments, infections, inflammatory disorders, menstrual problems, and urinary disorders. Furthermore, Thuja has been used to induce abortions.

  • Thuja is closely related to other cedar genera also used as dietary supplements, including as Cedrus (common name: cedar) and Juniperus (common name: juniper).

  • Very little scientific evidence exists regarding Thuja. Clinical trials evaluating Thuja alone are lacking, and the available data are questionable.

  • Preclinical studies have demonstrated anticancer and immune-stimulating properties, but further research is necessary. Thuja is often used in homeopathy as a remedy for skin, urinary, and reproductive organ complaints. The herb is also used in combination with Echinacea purpurea, Echinacea pallida, and Baptisia tinctoria to relieve symptoms of common cold and upper respiratory tract infections and as supportive therapy to standard antibiotics.

Scientific Evidence


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.

Common cold / upper respiratory tract infection

There is limited evidence that Esberitox®, a combination of Baptisia tinctoria root, Echinacea purpurea and pallida root, and Thuja occidentalis, may reduce symptoms of common colds and upper respiratory tract infections. However, the effect of Thuja alone is unclear. Further research is needed before a firm conclusion can be made.

*Key to grades:


The below uses are based on tradition or scientific theories. 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 health care professional.

  • Abortifacient (abortion inducer), anal fissures, angina (chest pain), antibiotic (supportive care to prevent immune system impairment caused by antibiotics), antiviral, arthritis, benign prostatic hypertrophy (BPH), bladder disorders, blood disorders, breast cancer, bronchitis, cancer, catarrh, chemotherapy side effect reduction, cleanser, constipation, diuresis (promotion of urination), eczema, endocrine disorders, eye disorders, flavoring agent, food additive, gout, gynecological disorders, hair dye, hair tonic, headache, heart conditions, hemorrhoids, HIV, immunostimulation, infections, inflammatory conditions, insecticide, labor induction, menstrual disorders, muscle aches, nasal polyps, nocturnal enuresis (bedwetting), onychomycosis (fungal infection of the nail), otitis media, prostate cancer, psoriasis, radiation therapy side effects, respiratory distress, rheumatism, sinusitis, skin conditions, syphilis, testicular damage, urinary disorders, uterine stimulant, warts.


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.

Adults (18 years and older)

  • To decrease the symptoms of colds and upper respiratory tract infections, 1-3 tablets of Esberitox®, which contains Baptisia tinctoria (wild indigo) root, Echinacea purpurea and pallida (coneflower) root, and Thuja occidentalis (white cedar) leaf, have been given by mouth three times daily for 3-12 days.

  • To treat infected or swollen eyes, 1-30 drops of full-strength or diluted Thuja have been applied to the surface of the eye.

  • To treat fluid-filled sacks in the scrotum, 1/8 ounce of Thuja has been mixed with one ounce of warm water and injected into the tunica vaganalis (covering of the testis).

  • There is a lack of scientific data available to accurately determine what dose of Thuja is toxic.

Children (under 18 years old)

  • There is no proven safe or effective dose for Thuja in children.


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.


  • Avoid in people with a known allergy or sensitivity to Thuja occidentalis or its parts.

  • People with work-related asthma may develop shingles after exposure to Thuja occidentalis.

  • Although not well studied in humans, Western red cedar and Eastern white cedar (Thuja occidentalis) allergies may cross-react.

Side Effects and Warnings

  • Reports of adverse effects associated with Thuja are limited. Use of Thuja in high doses is likely unsafe.

  • According to limited evidence, Thuja may cause burns, irritation of the uterus, rashes, severe eye irritation, skin irritation, and spontaneous abortion. High doses of Thuja may cause absorption disorders, breathing difficulties, convulsions, diarrhea, headache, heart bleeding, intestinal irritations, irregular heartbeat, liver damage, nervous agitation, stomach disorders, and vomiting.

  • Use cautiously in people with asthma, autoimmune disorders, or liver disorders.

  • Avoid using in people with a known allergy or sensitivity to Thuja occidentalis or its parts.

  • Avoid using in pregnant women, as traditionally Thuja has been used to cause miscarriages.

Pregnancy and Breastfeeding

  • There is currently little scientific evidence on the use of Thuja during pregnancy or lactation.

  • Due to historical reports describing the use of Thuja for its abortive properties, Thuja should likely be avoided in women who are pregnant or breastfeeding.


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.

Interactions with Drugs

  • Thuja may interact with agents that affect the immune system, agents that affect the liver, antibiotics, anticancer agents, and antiviral agents.

Interactions with Herbs and Dietary Supplements

  • Thuja may interact with antibacterials, anticancer agents, antiviral agents, herbs and supplements that affect the immune system, herbs and supplements that affect the liver, and herbs that contain thujone.

Author Information

  • This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).


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 www.naturalstandard.com. Selected references are listed below.

  1. Cartier A, Chan H, Malo JL, Pineau L, Tse KS, and Chan-Yeung M. Occupational asthma caused by eastern white cedar (Thuja occidentalis) with demonstration that plicatic acid is present in this wood dust and is the causal agent. J Allergy Clin Immunol. 1986;77(4):639-645. View Abstract
  2. Deane PM. Conifer pollen sensitivity in western New York: cedar pollens. Allergy Asthma Proc 2005;26(5):352-355. View Abstract
  3. Elsasser-Beile U, Willenbacher W, Bartsch HH, Gallati H, Schulte Monting J, and von Kleist S. Cytokine production in leukocyte cultures during therapy with Echinacea extract. J Clin Lab Anal. 1996;10(6):441-445. View Abstract
  4. Gohla SH, Haubeck HD, Schrum S, Soltau H, and Neth RD. Activation of CD4-positive T cells by polysaccharide fractions isolated from the Cupressaceae Thuja occidentalis L. (Arborvitae). Haematol.Blood Transfus. 1989;32:268-272. View Abstract
  5. Hauke W, Kohler G, Henneicke-von Zepelin HH, and Freudenstein J. Esberitox N as supportive therapy when providing standard antibiotic treatment in subjects with a severe bacterial infection (acute exacerbation of chronic bronchitis). A multicentric, prospective, double-blind, placebo-controlled study. Chemotherapy 2002;48(5):259-266. View Abstract
  6. Henneicke-von Zepelin H, Hentschel C, Schnitker J, Kohnen R, Kohler G, and Wustenberg P. Efficacy and safety of a fixed combination phytomedicine in the treatment of the common cold (acute viral respiratory tract infection): results of a randomised, double blind, placebo controlled, multicentre study. Curr Med Res Opin. 1999;15(3):214-227. View Abstract
  7. MacLaughlin BW, Gutsmuths B, Pretner E, Jonas WB, Ives J, Kulawardane DV, and Amri H. Effects of homeopathic preparations on human prostate cancer growth in cellular and animal models. Integr.Cancer Ther 2006;5(4):362-372. View Abstract
  8. Millet Y, Jouglard J, Steinmetz MD, Tognetti P, Joanny P, and Arditti J. Toxicity of some essential plant oils. Clinical and experimental study. Clin Toxicol. 1981;18(12):1485-1498. View Abstract
  9. Naser B, Bodinet C, Tegtmeier M, and Lindequist U. Thuja occidentalis (Arbor vitae): A Review of its Pharmaceutical, Pharmacological and Clinical Properties. Evid.Based Complement Alternat.Med 2005;2(1):69-78. View Abstract
  10. Naser B, Lund B, Henneicke-von Zepelin HH, Kohler G, Lehmacher W, and Scaglione F. A randomized, double-blind, placebo-controlled, clinical dose-response trial of an extract of Baptisia, Echinacea and Thuja for the treatment of patients with common cold. Phytomedicine. 2005;12(10):715-722. View Abstract
  11. Offergeld R, Reinecker C, Gumz E, Schrum S, Treiber R, Neth RD, and Gohla SH. Mitogenic activity of high molecular polysaccharide fractions isolated from the cuppressaceae Thuja occidentalis L. enhanced cytokine-production by thyapolysaccharide, g-fraction (TPSg). Leukemia 1992;6 Suppl 3:189S-191S. View Abstract
  12. Ramsewak RS, Nair MG, Stommel M, and Selanders L. In vitro antagonistic activity of monoterpenes and their mixtures against ‘toe nail fungus’ pathogens. Phytother.Res 2003;17(4):376-379. View Abstract
  13. Singh SK, Shanmugavel M, Kampasi H, Singh R, Mondhe DM, Rao JM, Adwankar MK, Saxena AK, and Qazi GN. Chemically standardized isolates from Cedrus deodara stem wood having anticancer activity. Planta Med 2007;73(6):519-526. View Abstract
  14. Sunila ES, Kuttan G. A preliminary study on antimetastatic activity of Thuja occidentalis L. in mice model. Immunopharmacol.Immunotoxicol. 2006;28(2):269-280. View Abstract
  15. Thangapazham RL, Gaddipati JP, Rajeshkumar NV, Sharma A, Singh AK, Ives JA, Maheshwari RK, and Jonas WB. Homeopathic medicines do not alter growth and gene expression in prostate and breast cancer cells in vitro. Integr.Cancer Ther 2006;5(4):356-361. View Abstract

The information in this monograph is intended for informational purposes only, and is meant to help users better understand health concerns. Information is based on review of scientific research data, historical practice patterns, and clinical experience. This information should not be interpreted as specific medical advice. Users should consult with a qualified healthcare provider for specific questions regarding therapies, diagnosis and/or health conditions, prior to making therapeutic decisions.