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This monograph is intended to serve as a guide to industry for the preparation of Product Licence Applications (PLAs) and labels for natural health product market authorization. It is not intended to be a comprehensive review of the medicinal ingredient.



August 28, 2018

Proper name(s), Common name(s), Source material(s)

Table 1. Proper name(s), Common name(s), Source material(s)
Proper name(s) Common name(s) Source material(s)
Proper name(s) Part(s) Preparation

Thuja occidentalis

  • American arborvitae
  • Arborvitae
  • Cedar
  • Eastern arborvitae
  • Eastern white cedar
  • Hackmatack
  • Northern white-cedar
  • Swamp cedar
  • Thuja
  • Tree of life
  • White-cedar

Thuja occidentalis

Herb top


References: Proper name: USDA 2018; Common names: McGuffin et al. 2000; Source material: BHP 1983, Felter and Lloyd 1983.

Route of Administration


Dosage Form(s)

This monograph excludes foods or food-like dosage forms as indicated in the Compendium of Monographs Guidance Document.

Acceptable dosage forms for the age category listed in this monograph and specified route of administration are indicated in the Compendium of Monographs Guidance Document.

Use(s) or Purpose(s)

Traditionally used in Herbal Medicine as an expectorant to help relieve bronchial mucus buildup (catarrh) (Hoffmann 2003; Williamson 2003; BHP 1983; Felter and Lloyd 1983).


Claims for traditional use must include the term "Herbal Medicine", "Traditional Chinese Medicine", or "Ayurveda".



Adults 18 years and older


Methods of preparation: Dry, Powder, Non-Standardised Extracts (Dry Extract, Tincture, Fluid Extract, Decoction, Infusion)

1 - 2 grams dried herb tops, 3 times per day (Williamson 2003; BHP 1983).

Direction(s) for use

No statement required.

Duration(s) of Use

For occasional use only (Brinker 2010; McGuffin 1997).

Risk Information

Caution(s) and warning(s)


Do not use this product if you are pregnant (Brinker 2010; Hoffmann 2003; BHP 1983).

Known adverse reaction(s)

No statement required.

Non-medicinal ingredients

Must be chosen from the current Natural Health Product Ingredient Database (NHPID) and must meet the limitations outlined in the database.

Storage conditions

No statement required.


References cited

References reviewed