Thuja oil, also known as cedar leaf oil, is a sweet-smelling oil with similarities to camphor. In appearance, thuja oil ranges from a clear yellow to completely colorless. It is drawn from the thuja occidentalis, or eastern white cedar, a tree native to the northeast portion of North America. Thuja oil has a strong, pleasant smell, which is why it often is used as a component in perfumes, colognes and other health and beauty products such as cosmetics, soaps and toiletries. Its aroma makes it a popular choice for scenting household cleaners, furniture and shoe polish. It also is a natural insect repellant and is used in some pesticides and repellant products.
The tree itself is a sturdy evergreen conifer closely related to the larger western red cedar. It has been cultivated as an ornamental plant and is primarily used for screens and hedgerows but also is grown and cut for lumber. Unlike many other conifers, the leaves of the eastern white cedar are not needle-shaped but are dark green, scaly fingers splayed in a flat fan shape. Thuja oil is drawn from these leaves.
American Indians were the first to use thuja oil as a medicine. As a rich source of Vitamin C, cedar leaves were used to prevent scurvy. Tea made from the leaves was used to treat menstrual pain and rheumatism. Preparations were made using cedar leaves to treat colds, burns and gout. The easter white cedar has been called the tree of life because of its reputed health benefits.
The oil’s medicinal properties have made it a popular herbal remedy and a common component in aromatherapy and homeopathy. Applied topically, it can be used as an astringent, a pain relief treatment for rheumatism, a remedy for external fungal infections and a wart remover. Inhaled, it can act as an expectorant, and it is an ingredient in well-known, over-the-counter congestion remedies and ointments. It has been used to treat insomnia, anxiety, psoriasis, eczema, heart palpitations, acne and dandruff, and as a diuretic, it is useful for detoxificion. Homeopathic preparations have been used to treat a wide variety of conditions, including headaches, back pain, venereal disease, infections, rashes, hemorrhoids, toothache, stomach pains, vertigo and even cancer.
Medical supervision is strongly recommended for those using thuja oil. High doses take by inhalation or ingestion can cause irritation to the digestive, respiratory, urinary and reproductive systems. One component of the oil in particular, thujone, is a potentially fatal neurotoxin that can cause muscle spasms, seizures and hallucinations when ingested. Thuja oil should not be taken by people with gastrointestinal complaints or seizure disorders. Thujone also is an abortifacient — a substance that triggers a miscarriage — and should not be taken by women during pregnancy or while breastfeeding.