Many are familiar with the major cannabinoids found in the Cannabis sativa L., (cannabis) plant, tetrahydrocannabinol (THC) and cannabidiol (CBD), which have great efficacy for conditions like depression, PTSD and epilepsy. But cannabinoids are only part of the picture. More than 200 terpenes are available in cannabis, while over 20,000 exist in nature. Primarily responsible for aroma and flavour, terpenes are secondary metabolites, fragrant oils which also offer a wide range of therapeutic benefits. Like amino acids, terpenes are powerful building blocks within plant physiology that aid in production of vitamins, hormones, pigments, resins, and cannabinoids in cannabis.
Terpenes are secreted alongside cannabinoids like THC and CBD, with both biosynthesised in the glandular trichomes, small resin glands primarily observed on the surface of the flowers and leaves of cannabis plants. Terpenes are very volatile, delicate molecules, easily destroyed by heat and oxidation and cannabis plants release more terpenes when temperatures are higher (one reason they emit stronger aromas during the peak of harvest).
As discussed in a previous article, Cannabis Terpenes and Their Benefits – Limonene, ancient cultures have used terpenes from a variety of aromatic herbs including cannabis for millennia to treat a wide variety of conditions. More modern research has confirmed the beliefs of ancient civilisations, revealing strong medicinal efficacy. There are about ten primary and twenty secondary terpenes that occur naturally in significant concentrations. β–Linalool (linalool), a monoterpene, has a boiling point of 198°C (388°F) and is best known for the pleasant floral scent reminiscent of spring flowers, with spicy overtones, it gives hundreds of different plants including lavender, citrus, cinnamon, laurel, birch, coriander, clary sage and rosewood.
Humans have inhaled the scent of certain plants, including many containing linalool, since ancient times to help lower stress levels, fight inflammation and combat depression. Linalool is a calmative and sleep aid (partly responsible for sedative effects of certain cannabis strains) and is a critical precursor in the formation of vitamin E. Linalool is found in highest concentrations (30-40%) in the essential oil of lavender and to a lesser extent in more than 200 species of aromatic plants, many of which are used traditionally as analgesic and anti-inflammatory remedies. Linalool is the ‘sweetness’ detected in many essential oils.
Twenty-five drops of lavender essential oil delivers around 0.3 grams of linalool.
The Lamiaceae plant and herb family, which includes mints and other scented herbs, is a common source of linalool. The Lauraceae plant family, which includes laurels, cinnamon and rosewood, is also a readily available source. The Rutaceae family, which contains citrus plants, is a third viable source. Birch trees and several different plant species found in tropical and boreal climate zones also produce linalool along with some fungi. Linalool is used in a wide variety of bath and body products and is commonly listed under ingredients as beta linalool, linalyl alcohol, linaloyl oxide, p-linalool and allo-ocimenol. Widely used (around 80% of all products) as a fragrance in cleaning and hygiene products, in the chemical industry and as an insecticidal vapour against flies, fleas and cockroaches.
Linalool serves many roles in relieving symptoms, including pain, depression, seizures, inflammation (similar to limonene) and even insomnia (acts as a sedative) and its tranquillising effects are helpful for those suffering with many types of psychosis. Many linalool-producing plant species are traditionally used as sedative, analgesic, hypnotic or anxiolytic (anti-anxiety) remedies in traditional medicine. The sedative, anxiolytic and anti-seizure effects have their mechanism of action based on the modulation of the glutamate and GABA neurotransmitters (glutamate is the main excitatory and GABA the main inhibitory neurotransmitter in the mammalian brain), similarly to the way cannabinoids act. Thus, a cannabis plant with both THC and linalool will probably produce a significant sedative and analgesic effect, due to the synergy between the two compounds. However, a cannabis plant with CBD and/or THCv and/or CBDv and linalool will probably produce a synergistic effect as an anti-seizure medication, which would be useful in cases of epilepsy, even as a preventive measure.
Linalool’s therapeutic effects include:
Analgesia – a pain killer, as elucidated in a 2003 study, ‘Linalool produces antinociception in two experimental models of pain’. Antinociception is the action or process of blocking detection of a painful or injurious stimulus by sensory neurons. In another more recent study (2016), ‘Odour-induced analgesia mediated by hypothalamic orexin neurons in mice‘, noted that linalool, “… significantly increased the pain threshold and attenuated pain behaviours … findings reveal central analgesic circuits triggered by olfactory input in the mammalian brain and support a potential therapeutic approach for treating pain with linalool odour stimulation“. The essential oil of lavender eases burns (topically) due to its antiseptic, anti-bacterial and circulatory stimulating properties and has been shown to reduce opiate intake when inhaled by patients undergoing post-operative pain treatment. Combined with cannabinoids of the same efficacy, linalool can be a reinforcing agent in managing painful conditions like Multiple Sclerosis (MS), dystonia, arthritis and other chronic conditions.
Anti-anxiety – anxiolytic effects on a comparable level to local anaesthetics such as lidocaine or menthol. 2008 research published in the American Association of Nurse Anesthetists Journal supported the sedative qualities of linalool. The study estimated 19 million Americans suffer from anxiety-related ailments, with 16% aged 18-54 being patients of one or more anxiety conditions, which sometimes lead to substance abuse and mood disorders. This study revealed linalool to be a powerful sedative that delivers real efficacy to those who suffer anxiety disorders and a most common side effect, insomnia. Concluded the study: “Our data … suggested that linalool modulates the central nervous system by producing unconsciousness and degradation of motor movements”. It has also been used in the treatment of psychosis.
Anti-convulsant – seizures afflict those with conditions other than epilepsy, including traumatic brain injury, brain tumours and hydrocephalus, for example. Seizures featuring a duration of less than two minutes, typically do not cause lasting harm, although very painful and exhausting for sufferers. A 2010 study involving mice that employed three different sub-types of linalool found it to be an effective anti-convulsant, showing significant promise for those who suffer seizures. Reported the study, “Linalool … was effective in preventing tonic convulsions induced by trans-corneal electroshock in … animals”.
Anti-depressant – more than 20 million people in the United States (US) and at least one million (annually) in Australia suffer from debilitating depression. This common psychological ailment can negatively affect education, career choices, personal relationships and physical health. Linalool, when combined with cannabinoids like THC, help alleviate depression. A 2015 study, ‘Linalool and β-pinene exert their antidepressant-like activity through the monoaminergic pathway‘, indicated both linalool and β-pinene produce an antidepressant-like effect.
Anti-inflammatory – sufferers of inflammation-based diseases, Crohn’s, arthritis, Alzheimer’s, asthma, fibromyalgia, dermatitis, IBS, lupus and Parkinson’s, among many others, gain benefit from the anti-inflammatory activity of linalool. A 2002 study in the Journal of Phytomedicine revealed linalool is a major anti-inflammatory
agent, potentially helping with a variety of inflammation-related ailments, such as cancer, arthritis and Crohn’s disease. The same research team, in a 2003 study, found linalool to also be an analgesic ( pain killer). In 2006 another linalool study further reinforced its use as a powerful anti-inflammatory. Linalool reverses the histopathological hallmarks of Alzheimer’s (2016 study) and restores cognitive and emotional functions via an anti-inflammatory effect. Linalool can also significantly reduce lung inflammation caused by cigarette smoke as shown by a study in 2015, ‘Linalool inhibits cigarette smoke-induced lung inflammation by inhibiting NF-κB activation’.
Anti-leukaemia / Chemo-preventive – shown to have anti-leukaemia spectrum and molecular mechanisms inhibiting tumour cell growth. In a 2010 study it was demonstrated linalool preferentially induced growth arrest and apoptosis of a variety of human leukaemia cells, but spared normal cells. The findings warrant further investigation of this class of natural product for developing novel therapeutic agents for leukaemia. A 2016 study, ‘The preventive effect of linalool on acute and chronic UVB-mediated skin carcinogenesis …’, evidenced topical or intraperitoneal treatment with linalool prevented acute UVB-induced hyperplasia, oedema formation, lipid peroxidation and antioxidant depletion, in mice.
Anti-seizure – linalool has properties that inhibit glutamatergic activity and also decrease the release of neurotransmitters of the neurons under glutamate stimulation. The abstract of a 2001 study, ‘Effects of Linalool on Glutamate Release and Uptake in Mouse Cortical Synaptosomes‘, states; “Linalool, a monoterpene compound prevalent in essential oil of plant species traditionally used as sedatives, has been characterised as anticonvulsant in several experimental models … linalool significantly reduced potassium-stimulated glutamate release as well as glutamate uptake, not interfering with basal glutamate release. The data indicates that linalool may interfere with several relevant elements of the glutamatergic transmission …“.
- Anti-chemotherapy-induced nausea and vomiting (CINV) – a 2016 study in the Journal of Pharmacology and Experimental Therapeutics, ‘Noncompetitive Inhibition of 5-HT3 Receptors by Citral, Linalool, and Eucalyptol Revealed by Nonlinear Mixed-Effects Modelling’, summarised the research outlining how they used nonlinear mixed-effects modelling to show the oils citral, eucalyptol and linalool inhibit 5-HT3 receptors via noncompetitive mechanisms. Compounds that selectively antagonise 5-HT3 receptors are the current gold-standard for treatment of chemotherapy-induced and post-operative nausea and vomiting and have potential for the treatment of a range of other conditions.
- Sedative / Sleep Aid – an estimated 10-30% of people suffer from insomnia at some point in their lives, with 10% reported to experience chronic and severe sleep deprivation. Cannabinoids like CBN, when combined with terpenes such as linalool, help patients get the sleep they require to maintain homoeostasis (balance) and good health. Adequate sleep is critical for patients to most effectively fight their condition or disease. Linalool has been the subject of many studies, including one in 2009 in the Journal of Agricultural and Food Chemistry, ‘Stress Repression in Restrained Rats by … Linalool Inhalation and Gene Expression Profiling …’ during which scientists allowed laboratory rats to inhale linalool while exposing them to stressful conditions. Linalool returned elevated stress levels in the immune system to near-normal conditions. In tests on humans who inhaled lavender essential oil, it caused severe sedation. In tests on laboratory rats it reduced their activity by almost 75%.
Expanded from Myrcene, Linalool, and Bisabolol, Taming THC, Antitumor Activity of Monoterpenes, Linalool Cannabis Terpene, Linalool produces antinociception, Cannabis Terpenes and How They Affect You, Terpenes, Chemistry and analysis of phytocannabinoids, Cannabinoids and Terpenes as Chemotaxonomic Markers, Plant terpenes, What is the terpene Linalool found in cannabis?, Linalool … Shown to Have Anti-Cancer Effects, Relationships of linalool, linalyl acetate and oxygenated derivatives
*Not every batch of any given strain will have high levels of any particular terpene as they are subjected to variable growing conditions. The only way to be sure is through a lab’s terpene analysis.