eucalyptus essential oil benefits

Eucalyptus essential oil

Eucalyptus oil is the generic name for distilled oil extracted from the leaves of Eucalyptus, a genus of the plant family Myrtaceae native to Australia and cultivated worldwide. Eucalyptus oil has a history of wide application, as a pharmaceutical, antiseptic, repellent, flavoring, fragrance and industrial uses. The leaves of selected Eucalyptus species are steam distilled to extract eucalyptus oil and and the oil are used to make medicine.

China produces about 75% of the world trade, but most of this is derived from the cineole fractions of camphor laurel rather than being true eucalyptus oil 1). Significant producers of true eucalyptus oil include South Africa, Portugal, Spain, Brazil, Australia, Chile, and Swaziland.

Though eucalyptus oil is used medicinally for many purposes, there isn’t enough scientific evidence so far to rate it as effective for any of them.

Eucalyptus leaf is used for infections, fever, upset stomach, and to help loosen coughs. The leaf is also used for treating respiratory tract infections, whooping cough, asthma, pulmonary tuberculosis, osteoarthritis, joint pain (rheumatism), acne, wounds, poorly healing ulcers, burns, bacterial dysentery, ringworms, liver and gallbladder problems, loss of appetite, and cancer.

Eucalyptus oil should not be taken by mouth or applied to the skin full-strength. It must be diluted for safety. Eucalyptus oil can be harmful in large amounts. The diluted oil is taken by mouth for pain and swelling (inflammation) of respiratory tract mucous membranes, coughs, bronchitis, sinus pain and inflammation, asthma, chronic obstructive pulmonary disease (COPD), and respiratory infections. It is also used as an expectorant to loosen coughs, antiseptic, fever reducer, and in vaporizer fluids. Other uses include treatment of wounds, burns, ulcers, and cancer.

Diluted eucalyptus oil is applied directly to the skin for pain and swelling of respiratory tract mucous membranes, joint pain, genital herpes, and nasal stuffiness. It is also used as an insect repellent.

In dentistry, eucalyptus oil is included in products used as sealers and solvents for root canal fillings.

In foods, dried eucalyptus leaf is used as a flavoring agent.

In manufacturing, eucalyptus oil is used as a fragrance in perfumes and cosmetics. It is also used as a mouthwash, antiseptic, liniment and ointment, and in toothpaste, cough drops, and lozenges.

The main group of constituents of eucalyptus oil is monoterpenes such as α-pinene, myrcene, cineole (eucalyptol), fenchone, α-terpinolene, and β-terpinyl acetate), and the principal constituent of pharmaceutical‐grade eucalyptus oil is eucalyptol (1,8‐cineole), which must comprise at least 70% of the contents (see Table 1) 2). Eucalyptus kochii and Eucalyptus polybractea have the highest cineole content, ranging from 80% to 95% 3). Global production is dominated by Eucalyptus globulus. The composition of the extracted oil can change depending on the storage conditions of the raw material and the technique employed to extract the oil 4).

Cineole-based “oil of eucalyptus” is generally considered safe for adults if taken at a low dose, as in the case of flavoring agents or in pharmaceutical products. However, at higher-than-recommended doses, systemic toxicity can occur 5). Darben et al. 6) has reported a toxicity of topical Eucalyptus experienced by a 6-years old Caucasians girl, resulted with nausea, slurred speech, ataxia, and muscle weaknesses after application of 25 mL of Eucalyptus globulus on her skin. Eucalyptus oil taken from the eucalyptus tree (true eucalyptus oil) does not contain camphor 7). However, the cineole fraction of camphor laurel that is also used to manufacture eucalyptus oil (which is considered “fake eucalyptus oil”) may contain camphor 8). Like eucalyptus oil, camphor is also epileptogenic 9), with recent case reports of two patients with eucalyptus oil poisoning, both adults who unintentionally took eucalyptus oil and presented to the emergency room of our institution with seizures 10). Most people, even physicians, are not aware of the toxic potential of these seemingly innocuous substances including Eucalyptus oil induced seizure. Regulation regarding the permissible limits of these ingredients in substances that contain them should be strictly imposed. Also, the label of products that contain eucalyptus oil or camphor should have mandatory warnings of the potential toxic effects, including seizures 11).

Table 1. Eucalyptus oil components

eucalyptus oil constituents

Footnote: Table 1 lists the major components of eucalyptus oil from five species. The percentage of components varies with species, plant part, and batch. Oil yield from Eucalyptus leaves ranging from 3.57-10.6 mg/g volatile components was demonstrated when various species were steam-distilled. Eucalyptus globulus produced 5.25 mg oil/g of fresh leaf 12).

[Source 13) ]

What dose of eucalyptus is used?

The appropriate dose of eucalyptus depends on several factors such as the user’s age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for eucalyptus. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.

What is eucalyptus oil good for?

Eucalyptol (1,8‐cineole) is a natural constituent of a number of aromatic plants including eucalyptus and their essential oil fraction. Eucalyptol (Cineole) is an organic compound which is a colorless liquid. Eucalyptol was given GRAS (Generally Recognized As Safe) status by the Flavor and Extract Manufacturer’s Association FEMA, 1965 and is approved by the Food and Drug Administration for food use. In a 1994 report released by five top cigarette companies, eucalyptol was listed as one of the 599 additives to cigarettes. It is added to improve the flavor 14).

Eucalyptus oil contains α-pinene and 1,8-cineole (also called Eucalyptol) and acts as an antioxidant, with strong radical scavenging activity 15). In a mouse model of pain-causing edema in the feet, oral administration of 1,8-cineole (Eucalyptol), which accounts for 70–90% (w/w) of the contents of eucalyptus oil, suppressed edema formation and reduced inflammation and pain 16). This effect of 1,8-cineole (Eucalyptol) is due to its inhibition of cytokine secretion by T-lymphocytes 17). Electromyography has shown that application of eucalyptus oil to a healthy subject had a myorelaxant effect, as well as promoting emotional stability 18). Moreover, in a rat model of susceptibility to pain from a hot plate, eucalyptus oil was not only analgesic but reduced edema formation and had an anti-inflammatory effect 19).

The cineole-based of eucalyptus oil is used as component in pharmaceutical preparations to relieve the symptoms of influenza and colds, in products like cough sweets, lozenges, ointments and inhalants. Eucalyptus oil may have antibacterial effects on pathogenic bacteria in the respiratory tract 20). Inhaled eucalyptus oil vapor is a decongestant and treatment for bronchitis 21). Cineole may control airway mucus hypersecretion and asthma via anti-inflammatory cytokine inhibition although there is insufficient evidence. Pre-clinical results also show that eucalyptus oil stimulates innate cell-mediated immune response by effects on the phagocytic ability of human monocyte derived macrophages 22).

The main chemical components of Eucalyptus oil, eucalyptol and alpha-terpineol, give the essential oil a soothing, cooling vapor. This makes Eucalyptus oil useful for massage.

Early research has shown Eucalyptus oil may have anti-inflammatory and analgesic qualities in as a topically applied liniment ingredient 23).

Eucalyptus oil is also used in personal hygiene products for antimicrobial properties in dental care 24) and soaps. It can also be applied to wounds to prevent infection 25).

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, Ineffective, and Insufficient Evidence to Rate.

The effectiveness ratings for EUCALYPTUS are as follows:

Eucalyptus oil is Possibly effective for:

Chronic obstructive pulmonary disease (COPD)

Cineole (eucalyptol), a chemical found in eucalyptus oil, has mucolytic, bronchodilating and anti-inflammatory properties and reduces the exacerbation rate in patients suffering from chronic obstructive pulmonary disease (COPD), as well as ameliorates symptoms in patients suffering from asthma and rhinosinusitis. As part of a double-blind, placebo-controlled, multi-center-study, a total of 242 patients with confirmed acute bronchitis was randomly selected to participate 26). Over a period of 10 days, all patients were administered 3 x 200 mg of Cineole, or a respective placebo, per day. The primary outcome measure was a Bronchitis Sum Score, which summarizes the relevant symptoms of acute bronchitis. After 4 days of treatment it was notable, that the patient group treated with Cineole, showed significantly more improvements of the bronchitis-sum-score than those of the placebo group. The statistical significant difference of the individual outcome measures was especially underlined by the frequency of cough fits after 4 days. The effects of Cineole in the treatment of acute bronchitis were clearly measurable and could be proven after a treatment period of merely 4 days. This study corroborates the fact that Cineole actively and significantly reduces cough frequency after four days 27).

In another double-blind, placebo-controlled multi-center-study where 242 patients were randomly assigned with stable chronic obstructive pulmonary disease (COPD) to receive 200 mg of cineole or placebo 3 times daily as concomitant therapy for 6 months during winter-time 28). The frequency, duration and severity of exacerbations were combined as primary outcome measures for testing as multiple criteria. Secondary outcome measures included changes of lung function, respiratory symptoms and quality of life as well as the single parameters of the exacerbations. Baseline demographics, lung function and standard medication of both groups were comparable. During the treatment period of 6 months the multiple criteria frequency, severity and duration of exacerbations were significantly lower in the group treated with cineole in comparison to placebo. Secondary outcome measures validated these findings. Improvement of lung function, dyspnea and quality of life as multiple criteria were statistically significant relative to placebo. Adverse events were comparable in both groups. Concomitant therapy with cineole reduces exacerbations as well as dyspnea and improves lung function and health status. This study 29) further suggests cineole as an active controller of airway inflammation in COPD by intervening in the pathophysiology of airway inflammation of the mucus membrane.

Acute bronchitis

In other studies, research shows that taking a specific combination product containing eucalyptol (1,8-cineole), a chemical found in eucalyptus oil, and extracts of pine and lime by mouth for at least 2 weeks improves symptoms and reduces flare-ups in people with bronchitis 30), 31), 32).

Asthma

Leukotriene B4 (LTB4) and prostaglandin E2 (PGE2), both produced in the pathway of arachidonic acid metabolism, were measured in stimulated monocytes from 10 patients with bronchial asthma and 12 healthy controls after treatment with eucalyptol (1,8‐cineole) (200 mg three times daily) for three days 33). Forced expiratory volume in one second (FEV1) and airway resistance were measured the day before treatment, during treatment, and after discontinuing treatment. Significant inhibition of LTB4 and PGE2 was observed in both groups. The FEV1 increased by 23.7 percent and airway resistance decreased by 26.1 percent after three days of eucalyptol treatment 34). When lung function was checked four days after the end of treatment, FEV1 (28.7%) and airway resistance (-17.6%) were still significantly improved compared to before treatment 35).

The anti-inflammatory effect of oral euclyptol (1.8-cineole) (200 mg three times daily) was demonstrated in a double-blind, placebo-controlled, 12-week trial of asthma patients 36). The required oral glucocorticoid dosage was decreased by a mean of 3.75 mg in the euclyptol group compared to 0.91 mg in the control group. Prednisolone dose prior to treatment was 5-24 mg daily with average of 11 mg. Of note, the use of the rescue medication salbutamol (albuterol) was increased almost two-fold in the control group when prednisolone was lowered by 2.5 mg; whereas, there was no significant increase in rescue puffs in the euclyptol group, even with a decrease of 5 mg prednisolone 37). Some participants dropped out at that reduction (four in the euclyptol group, 11 in the placebo group). The euclyptol group maintained lung function capacity (peak expiratory flow rate, FEV1, and airway resistance) four times longer than placebo, even at a lower prednisolone dosage 38).

Rhinosinusitis

A study showed that euclyptol (1.8-cineole) is effective for the discomforts of non-purulent rhinosinusitis 39). Individuals (n=150) with subjective findings of headache with or without bending, tenderness to pressure points of the trigeminal nerve, impairment of general condition, nasal obstruction, and nasal secretions (rated by quantity and viscosity) were randomized in a double-blind, placebo-controlled trial 40). Subjects in the treatment group (n=75) showed over 80-percent improvement after seven days of oral 1,8-cineole (200 mg three times daily) compared to less than 50-percent improvement in the placebo group 41). Improvement was determined by symptoms-sum-score. Ultra-sonography at the end of the study showed that sinus shadowing remained in 37 patients in the placebo group and four patients in the euclyptol group. All patients also inhaled 100 mcg of the decongestant xylometazoline three times daily to relieve nasal congestion 42).

Eucalyptus oil – Insufficient evidence to rate effectiveness for:

  • Arthritis. Early research suggests that aromatherapy with a combination of eucalyptus oil, lavender, marjoram, rosemary, and peppermint oils might reduce pain and depression in people with arthritis.
  • Asthma. Early research suggests that eucalyptol, a chemical found in eucalyptus oil, might be able to break up mucous in people with asthma. Some people with severe asthma have been able to lower their dosage of steroid medications if they take eucalyptol 43). But don’t try this without your healthcare provider’s advice and monitoring.
  • Dental plaque. Early research suggests that chewing gum containing 0.3% eucalyptus extract might reduce dental plaque in some people 44), 45), 46).
  • Headache. Early research suggests that applying a combination product containing eucalyptus oil, peppermint oil, and ethanol to the head does not reduce pain in people with headaches. However, the product might help people with headaches relax and think better 47).
  • Stuffy nose 48).
  • Wounds 49).
  • Burns.
  • Ulcers.
  • Acne.
  • Bleeding gums.
  • Bladder diseases.
  • Diabetes.
  • Fever.
  • Flu 50).
  • Liver and gallbladder problems.
  • Loss of appetite.
  • Other conditions 51), 52), 53).

More evidence is needed to rate the effectiveness of eucalyptus for these uses.

Eucalyptus safety concerns

Toxicological data available on eucalyptol (1,8-cineole) are rather limited, however, eucalyptus leaf is LIKELY SAFE when consumed in the small amounts found in foods. There isn’t enough information to know if supplements that contain larger amounts of eucalyptus leaf are safe when taken by mouth 54).

Eucalyptol, a chemical that is removed from eucalyptus oil and used as medicine, is POSSIBLY SAFE when taken by mouth for up to 12 weeks.

Eucalyptus oil is POSSIBLY UNSAFE when applied directly to the skin without first being diluted 55). Eucalyptus oil is LIKELY UNSAFE when it is taken by mouth without first being diluted. Taking 3.5 mL of undiluted oil can be fatal. Signs of eucalyptus poisoning might include stomach pain and burning, dizziness, muscle weakness, small eye pupils, feelings of suffocation, and some others. Eucalyptus oil can also cause nausea, vomiting, and diarrhea.

Eucalyptus oil side effects and poisoning

Eucalyptus oil poisoning is rare in adults but is not that uncommon in children 56) and it is usually unintentional 57). In the literature, eucalyptus oil poisoning in children presented with various clinical syndromes 58). The common Eucalyptus oil side effects in children include depression in the level of consciousness, ataxia, seizures, and vomiting 59). These manifestations can occur with therapeutic dosage or overdose. In children, the first episode of seizures or breakthrough seizures can occur with eucalyptus oil ingestion 60). Unlike in children, seizures are unusual in adult patients with eucalyptus oil poisoning 61). Most people, even physicians, are not aware of the toxic potential of these seemingly innocuous substances including Eucalyptus oil induced seizure. Regulation regarding the permissible limits of these ingredients in substances that contain them should be strictly imposed. Also, the label of products that contain eucalyptus oil or camphor should have mandatory warnings of the potential toxic effects, including seizures 62).

Table 2. Profile of patients with eucalyptus oil–induced seizures

Time to seizure (minutes)Duration of seizure (minutes)Type of seizurePostictal drowsiness (min)History of febrile seizurePast history of seizureFamily history of seizureHistory of previous use of eucalyptus oilMRI Electroencephalogram (EEG)Antiepileptic drug duration of treatment (weeks)Follow‐up (months)Recurrence
515generalized tonic‐clonic seizures15NoNoNoNoNormalRight frontal slowingLevetiracetam (2 weeks)4No
55generalized tonic‐clonic seizures20NoNoNoNoNormalNormalLevetiracetam3No
25generalized tonic‐clonic seizures20NoNoNoNoNormalNormalLevetiracetam (4 weeks)3No
23generalized tonic‐clonic seizures15NoNoNoNoNormalNormalNo treatment3No
53generalized tonic‐clonic seizures30NoNoNoNoNormalNormalNo treatment12No
33generalized tonic‐clonic seizures30NoNoNoNoNormalBifrontal and temporal slowingLevetiracetam (4 weeks)4No
108complex partial seizures (patient was in a state of altered sensorium for 10 minutes)10NoNoNoNoNANANo treatment2No
53generalized tonic‐clonic seizures20NoYesNoNoNormalNormalPrevious topiramate continued12No
21complex partial seizures (patient was in a state of altered sensorium for 10 minutes)10NoNoNoNoNormalNormalNo treatment24No
[Source 63) ]

Special precautions and warnings

Pregnancy and breast-feeding: Eucalyptus is LIKELY SAFE for pregnant and breast-feeding women when consumed in food amounts. But don’t use eucalyptus oil. Not enough is known about safety during pregnancy or breast-feeding.

Children: Eucalyptus oil is LIKELY UNSAFE for children. It should not be taken by mouth or applied to the skin. Not much is known about the safety of using eucalyptus leaves in children. It’s best to avoid use in amounts larger than food amounts 64).

Diabetes: Early research suggests eucalyptus leaf might lower blood sugar. There is concern that using eucalyptus while taking medications for diabetes might lower blood sugar too much. Blood sugar levels should be monitored closely.

Surgery: Since eucalyptus might affect blood sugar levels, there is concern that it might make blood sugar control difficult during and after surgery. Stop using eucalyptus at least 2 weeks before a scheduled surgery.

Eucalyptus interactions with herbs and supplements

Herbs and supplements that might lower blood sugar

Eucalyptus leaf might lower blood sugar. Using it with other herbs and supplements that have this same effect might increase the risk of low blood sugar in some people. Some of these products include alpha-lipoic acid, bitter melon, carqueja, chromium, devil’s claw, fenugreek, garlic, guar gum, horse chestnut, jambolan, Panax ginseng, prickly pear cactus, psyllium, Siberian ginseng, and others.

Herbs that contain hepatotoxic pyrrolizidine alkaloids

Eucalyptus can increase the toxicity of herbs that contain hepatotoxic pyrrolizidine alkaloids (PAs). PAs can damage the liver. Herbs containing hepatotoxic PAs include alkanna, boneset, borage, butterbur, coltsfoot, comfrey, forget-me-not, gravel root, hemp agrimony, and hound’s tongue; and the Senecio species plants dusty miller, groundsel, golden ragwort, and tansy ragwort.

Eucalyptus interactions with medications

Be cautious with this combination.

Aminopyrine

Inhaling eucalyptol, a chemical found in eucalyptus oil, might reduce the level of aminopyrine in the blood. In theory, the effectiveness of aminopryine may be reduced in people who inhale eucalyptol.

Amphetamines

Inhaling eucalyptol, a chemical found in eucalyptus oil, might reduce the levels of amphetamines in the blood. In theory, the effectiveness of amphetamines may be reduced in people who inhale eucalyptol.

Medications changed by the liver (Cytochrome P450 1A2 (CYP1A2) substrates)

Some medications are changed and broken down by the liver. Eucalyptus oil might decrease how quickly the liver breaks down some medications. Taking eucalyptus oil along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking eucalyptus oil, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include amitriptyline (Elavil), haloperidol (Haldol), ondansetron (Zofran), propranolol (Inderal), theophylline (Theo-Dur, others), verapamil (Calan, Isoptin, others), and others.

Medications changed by the liver (Cytochrome P450 2C19 (CYP2C19) substrates)

Some medications are changed and broken down by the liver. Eucalyptus oil might decrease how quickly the liver breaks down some medications. Taking eucalyptus oil along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking eucalyptus oil, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include omeprazole (Prilosec), lansoprazole (Prevacid), and pantoprazole (Protonix); diazepam (Valium); carisoprodol (Soma); nelfinavir (Viracept); and others.

Medications changed by the liver (Cytochrome P450 2C9 (CYP2C9) substrates)

Some medications are changed and broken down by the liver. Eucalyptus oil might decrease how quickly the liver breaks down some medications. Taking eucalyptus oil along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking eucalyptus oil, talk to your healthcare provider if you take any medications that are changed by the liver.

Some medications that are changed by the liver include diclofenac (Cataflam, Voltaren), ibuprofen (Motrin), meloxicam (Mobic), and piroxicam (Feldene); celecoxib (Celebrex); amitriptyline (Elavil); warfarin (Coumadin); glipizide (Glucotrol); losartan (Cozaar); and others.

Medications changed by the liver (Cytochrome P450 3A4 (CYP3A4) substrates)

Some medications are changed and broken down by the liver. Eucalyptus oil might decrease how quickly the liver breaks down some medications. Taking eucalyptus oil along with some medications that are broken down by the liver can increase the effects and side effects of some medications. Before taking eucalyptus oil, talk to your healthcare provider if you are taking any medications that are changed by the liver.

Some medications changed by the liver include lovastatin (Mevacor), ketoconazole (Nizoral), itraconazole (Sporanox), fexofenadine (Allegra), triazolam (Halcion), and many others.

Medications for diabetes (Antidiabetes drugs)

Eucalyptus leaf extract might decrease blood sugar. Diabetes medications are also used to lower blood sugar. Taking eucalyptus leaf extract along with diabetes medications might cause your blood sugar to go too low. Monitor your blood sugar closely. The dose of your diabetes medication might need to be changed.

Some medications used for diabetes include glimepiride (Amaryl), glyburide (DiaBeta, Glynase PresTab, Micronase), insulin, pioglitazone (Actos), rosiglitazone (Avandia), chlorpropamide (Diabinese), glipizide (Glucotrol), tolbutamide (Orinase), and others.

Pentobarbital (Nembutal)

Inhaling eucalyptol, a chemical found in eucalyptus oil, might reduce the amount of pentobarbital that reaches the brain. In theory, the effectiveness of pentobarbital may be reduced in people who inhale eucalyptol.

Eucalyptus oil overdose

Following the accidental exposure of human beings, death was reported in two cases after ingestion of 3.5-5 ml of essential eucalyptus oil, but a number of recoveries have also been described for much higher amounts of oil.

Eucalyptus oil overdose occurs when someone swallows a large amount of a product that contains this oil. This can be by accident or on purpose.

If you or someone you are with overdoses, call your local emergency number.

Do NOT induce vomiting. If vomiting occurs, lean patient forward or place on left side (head-down position, if possible) to maintain an open airway and prevent aspiration. Keep patient quiet and maintain normal body temperature. For eye contamination, flush eyes immediately with water. Irrigate each eye continuously with 0.9% saline during transport to the hospital.

Symptoms of Eucalyptus oil overdose

Below are symptoms of a eucalyptus oil overdose in different parts of the body.

AIRWAYS AND LUNGS

  • Rapid breathing
  • Shallow breathing
  • Wheezing

EYES, EARS, NOSE, THROAT, AND MOUTH

  • Difficulty swallowing
  • Burning sensation in mouth
  • Tiny pupils

HEART AND BLOOD

  • Rapid, weak heartbeat
  • Low blood pressure

MUSCLES AND JOINTS

  • Muscle weakness

NERVOUS SYSTEM

  • Drowsiness
  • Headache
  • Unconsciousness
  • Dizziness
  • Seizures
  • Slurred speech

SKIN

  • Redness and swelling (from the oil touching the skin)

STOMACH AND INTESTINES

  • Abdominal pain
  • Diarrhea
  • Nausea and vomiting

Home Care

Seek medical help right away. DO NOT make the person throw up unless poison control or a health care provider tells you to.

If the oil is on the skin or in the eyes, flush with lots of water for at least 15 minutes.

Outlook (Prognosis) of Eucalyptus oil overdose

Survival past 48 hours is usually a good sign that recovery will occur. If any damage to the kidneys has occurred, it may take several months to heal. Drowsiness may persist for several days.

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