Clove (Eugenia aromatica) and clove oil(eugenol)
Natural Standard Bottom Line Monograph, Copyright © 2013 (www.naturalstandard.com). Commercial distribution prohibited. This monograph is intended for informational purposes only, and should not be interpreted as specific medical advice. You should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.
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.
2-methoxy-4-(2-propenyl)-phenol, beta-caryophyllene, Caryophylli atheroleum,Caryophylli flor, caryophyllum, caryophyllus, Caryophyllus aromaticus, cengke (Indonesian), cengkeh (Indonesian), cinnamon nails, clavo (Spanish), clavo de olor (Spanish), clou de girofle (French), clove bud, clove bud oil, clove cigarettes, clove essential oil, clove leaf, clove oil, craveiro da India (Portuguese), cravina de Túnis (Portuguese), cravinho (Portuguese), cravo (Portuguese), cuisoare, dried clove, Eugenia aromatica, Eugenia bud, Eugenia caryophyllata, Eugenia caryophyllus, eugenol, eugenole, flores Caryophylli, Myrtaceae (family), oil of clove, oleum caryophylli, pentogen (clove oil), Syzigium aromaricum, Syzygium aromaticum (L) Merr. & Perry., Tiger Balm™ Red, tropical myrtle.
Do not confuse clove with: Baguacu, black plum, Eugenia cumini, Eugenia edulis, Eugenia jambolana, Eugenia umbelliflora, jamun, java apple, java plum, SCE, Syzygium cordatum, Syzygium cumini, Syzygium samarangense, water apple, or wax apple.
Combination product examples: Dent-Zel-Ite® toothache relief drops, Red Cross Toothache Medication®; Tiger Balm™ Red (5% cassia oil plus 5% clove oil); Shitei-To (STT) (Shitei (SI, Kaki Calyx; calyx of Diospyros kaki L. f.), Shokyo (SK, Zingiberis Rhizoma; rhizome of Zingiber officinale Roscoe) and Choji (CJ, Caryophylli flos; flowerbud of Syzygium aromaticum [L.] Merrill et Perry), Olbas Oil (menthol 4.1% and oil of cajuput 18.5%, clove 0.1%, eucalyptus 35.5%, juniper berry 2.7%, peppermint 35.5%, and wintergreen oil (methyl salicylate) 3.7%), Buddha Nose Immune Booster Spray and Salve (lemon, clove, cinnamon, and ravensara essential oils), DHC-1 (Bacopa monniera, Emblica officinalis, Glycyrrhiza glabra, Mangifera indica, and Syzygium aromaticum).
Dental sealants containing eugenol: Kerr Pulp Canal Sealer, Roth's 801, Eugenol-based IRM (Intermediate Restorative Material), Tifell (formocresol-eugenol), Pulp Canal Sealer, EndoFill.
Cement/temporary cement/periodontal dressings for dental work: ZOE®/SSW, Superbite, Canals, Endomethansone, N2, Endofill, Intrafill, Tubli-Seal, Kerr, periodontal dressings, Wondrpak® and Nobetec®, temporary cement Temp bond, Provy, TempCem, Eugedain, Showa Yakuhin Kakou, Pulp Canal Sealer EWT.
Clove is widely cultivated in Indonesia, Sri-Lanka, Madagascar, Tanzania, and Brazil. It is used in limited amounts in food products as a fragrant, flavoring agent, and antiseptic.
Clinical trials assessing monotherapy of clove are limited, although the expert panel German Commission E has approved the use of clove as a topical antiseptic and anesthetic. Other uses for clove, such as premature ejaculation, dry socket, and fever reduction, lack reliable human clinical evidence.
Clove is sometimes added to tobacco in cigarettes, and clove cigarettes ("kreteks") typically contain 60% tobacco and 40% ground cloves.
Eugenol, a constituent of clove, has been used for analgesic, local anesthetic, anti-inflammatory, and antibacterial effects. It is used in the form of a paste or mixture as dental cement, filler, and restorative material.
Plant oils, including clove, may be used in livestock to inhibit microbial fermentation in waste products. Clove oil may be found in high concentration licorice (glycyrrhizin) products to prevent gel formation in an aqueous solution.
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.
Clove essential oil is commonly used as a dental pain reliever. Early studies have found that a homemade clove gel may be as effective as benzocaine 20% gel. Clove oil combined with zinc oxide paste may be effective for dry socket (inflammation after tooth extraction).
Based on limited human study, 1% clove oil cream may have beneficial effects for the healing of anal fissures. More well-designed trials are needed before a conclusion may be made.
Based on clove oil's reported antibacterial effects, it may be useful for inclusion in methods of dental hygiene, such as toothpastes. One study did not show that clove oil, in combination with other supposed antibacterial agents, decreased the presence of bacteria in orthodontic patients. However, better designed studies are needed to determine the effects of clove oil alone before a conclusion may be made.
Animal studies suggest that clove can lower fever, but reliable human studies are lacking.
Headache (acute tension)
Based on limited study, clove bud oil, in combination with a variety of substances, may decrease headache severity. However, additional studies are needed to determine the effects of clove oil alone before a conclusion may be made.
In lab and field tests, undiluted clove oil repelled multiple species of mosquitoes for up to two hours. However, undiluted clove oil may also cause skin rash in sensitive people.
A small amount of human research reports that a combination cream with clove and other herbs may be helpful in the treatment of premature ejaculation. However, well-designed studies of the effectiveness of clove alone are needed before a conclusion can be drawn.
*Key to grades:A: Strong scientific evidence for this use; B: Good scientific evidence for this use; C: Unclear scientific evidence for this use; D: Fair scientific evidence against this use (it may not work); F: Strong scientific evidence against this use (it likely does not work).
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.
Abdominal pain, acaricidal (an agent that destroys mites), acne, allergies, analgesic (pain reliever), anesthetic, anthelmintic, antibacterial, antifungal, anti-gas, antihistamine, anti inflammatory, antimicrobial, antimutagenic, antioxidant, antiseptic, antispasmodic, antiviral, aphrodisiac, asthma, atherosclerosis (hardening of the arteries), athlete's foot, bad breath, blood purifier, blood thinner (antiplatelet agent), cancer, cavities, cholagogue (promotes the discharge of bile from the liver and the gallbladder), chronic venous insufficiency, cleansing, colic, cough, counterirritant, decreased gastric transit time, dental plaque and gingivitis (mouthwash), diabetes, diagnosis of allergies (wasp venom), diarrhea, dyspepsia, edema (oral), expectorant, flavoring (for food and cigarettes), food preservative, general health maintance, gout, hernia, herpes simplex virus, hiccups, high blood pressure, inflammation, insecticidal, insulin mimetic, intestinal parasites, libido, lice, lipid-lowering, liver toxicity, measles, mouth and throat inflammation, muscle aches, nausea (during pregnancy), nausea or vomiting, neurodegeneration, neuroprotection, oral candidiasis (thrush), pain, parasites, protection against asbestos-related lung injury, rash, rheumatic diseases, ringworm, smooth muscle relaxant (clove oil), solvent (drug-delivery system), stomach pain, toxicity (prevention of arsenite-induced toxicity), ulcers, vaginal candidiasis (prevention and treatment), vasorelaxant (clove oil).
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)
There is not enough scientific evidence available to recommend a specific dose of clove by mouth, on the skin, or by any other route. However, based on expert opinion, intake should not exceed 2.5 milligrams per kilogram of body weight each day. For anal fissures, a preparation of 1% clove oil cream for six weeks has been studied. For dental pain, a dose of 2 grams of homemade clove gel (made by grinding commercially available clove and mixing it with a clove-to-glycerin mixture in a ratio of 2:3) has been applied to inside the mouth for four minutes and then reapplied for another minute. As a mosquito repellent, a dose of 0.1 milliliters of clove oil of different concentrations (5, 10, 25, 50, 75, and 100%) per 30cm2 of exposed skin has been studied.
Children (younger than 18 years)
There is not enough scientific evidence available to recommend a specific dose of clove by mouth, on the skin, or by any other route.
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.
Allergic reactions to clove, its component eugenol have been reported, including possible severe reactions (anaphylaxis). Signs of allergy may include rash, itching or shortness of breath. Eugenol or clove can cause allergic rashes when applied to skin or inside the mouth. Hives have been reported in clove cigarette smokers. Individuals with known allergy to clove, its component eugenol, or to Balsam of Peru should avoid the use of clove by mouth, inhaled from cigarettes, or applied to the skin.
Side Effects and Warnings
Clove is generally regarded as safe for food use in the United States. However, when clove is taken by mouth in large doses, in its undiluted oil form, or used in clove cigarettes, side effects may occur including vomiting, sore throat, seizure, sedation, difficulty breathing, fluid in the lungs, vomiting of blood, blood disorders, kidney failure, and liver damage or failure. People with kidney or liver disorders or who have had seizures should avoid clove. Serious side effects are reported more often in young children, even with small doses, and therefore clove supplements should be avoided in children and pregnant or nursing women.
Clove or clove oil may cause an increased bleeding risk, based largely on laboratory research. Caution is advised in patients with bleeding disorders or taking drugs that may increase the risk of bleeding. Dosing adjustments may be necessary. It is not clear what doses or methods of using clove may increase this risk. Clove use should be stopped before surgery.
When applied to the skin or inside of the mouth, clove can cause burning, loss of sensation or painful sensation, local tissue damage, dental pulp damage, higher risk of cavities, or sore lips. Undiluted clove oil has a high risk of causing contact dermatitis (rash) and even burns if applied to the skin at full strength. The application of clove combination herbal creams to the penis has been said to cause episodes of difficulty with erection or ejaculation.
Clove oil taken by mouth may lower blood sugar levels. Caution is advised in patients with diabetes or hypoglycemia, and in those taking drugs, herbs, or supplements that affect blood sugar. Serum glucose levels may need to be monitored by a healthcare provider, and medication adjustments may be necessary.
Ingestion of clove oil may cause liver or kidney damage. Caution is advised in patients with liver or kidney disease.
Eugenol, a component of clove oil, may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.
Eugenol may inhibit estrogen. Caution is advised in patients taking hormone replacement therapy.
Eugenol and clove oil may cause male infertility. Caution is advised in individuals trying to get pregnant.
Eugenol may modulate the immune system. Caution is advised in patients with autoimmune disorders or those taking agents that suppress the immune system.
Use cautiously with anthelmintics, antibiotics, antifungals, anti-inflammatories, antihistamines, antineoplastics, antiprotozoals, anti-seizure agents, anti-spasm agents, antivirals, fertility agents, drugs that inhibit tyrosinase, and vasodilators. Clove may also affect the way in which the liver breaks down certain drugs.
Contamination can occur if clove is improperly stored.
Pregnancy and Breastfeeding
Not enough information about safety is available to recommend the use of clove supplements in pregnant or breastfeeding women.
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
Based on laboratory research, clove theoretically may increase the risk of bleeding when taken with drugs that increase the risk of bleeding. It is not clear what doses or methods of using clove may increase this risk. Some examples of drugs that increase bleeding risk include aspirin, anticoagulants ("blood thinners") such as warfarin (Coumadin®) or heparin, anti-platelet drugs such as clopidogrel (Plavix), and non-steroidal anti-inflammatory drugs such as ibuprofen (Motrin®, Advil®) or naproxen (Naprosyn®, Aleve®).
Clove oil taken by mouth may lower blood sugar levels. Caution is advised when using medications that may also lower blood sugar. Patients taking drugs for diabetes by mouth or insulin should be monitored closely by a qualified healthcare provider. Medication adjustments may be necessary.
When applied to the skin, eugenol, a component of clove, may reduce the ability to feel and react to painful stimulation. Therefore, use of clove products on the skin with other numbing or pain-reducing products such as lidocaine/prilocaine cream (Emla®) theoretically may increase effects.
Clove may also react with anthelmintics, antibiotics, antifungals, anti-inflammatories, antihistamines, antineoplastics, antiprotozoals, anti-seizure agents, anti-spasm agents, antivirals, drugs that cause adverse dental effects, drugs taken for cardiovascular conditions, drugs that suppress the immune system, drugs that are toxic to the kidneys, estrogens, fertility agents, agents that are toxic to the liver, drugs that inhibit tyrosinase, and vasodilators. Clove may also affect the way in which the liver breaks down certain drugs.
Interactions with Herbs and Dietary Supplements
Based on laboratory research, clove may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. It is not clear what doses or methods of using clove may increase this risk. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, some cases with garlic, and fewer cases with saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
Clove may lower blood sugar levels. Caution is advised when using herbs or supplements that may also lower blood sugar. Blood glucose levels may require monitoring, and doses may need adjustment.
When applied to the skin, eugenol, a component of clove, may reduce the ability to feel and react to painful stimulation. Therefore, use with other numbing or pain-reducing products such as capsaicin cream (Zostrix®) may in theory cause exaggerated effects.
Clove may also react with anthelmintics, antibacterials, antifungals, anti-inflammatories, antihistamines, antineoplastics, antiprotozoals, anti-seizure agents, anti-spasm agents, antivirals, herbs or supplements that cause adverse dental effects, herbs or supplements taken for cardiovascular conditions, herbs or supplements that suppress the immune system, herbs or supplements that are toxic to the kidneys, estrogens, fertility herbs or supplements, herbs or supplements that are toxic to the liver, herbs or supplements that inhibit tyrosinase, and vasorelaxant herbs and supplements.. Clove may also affect the way in which the liver breaks down certain herbs.
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.
Alqareer A, Alyahya A, Andersson L. The effect of clove and benzocaine versus placebo as topical anesthetics. J Dent 2006;34(10):747-50. View Abstract
Chami N, Bennis S, Chami F, et al. Study of anticandidal activity of carvacrol and eugenol in vitro and in vivo. Oral Microbiol.Immunol 2005;20(2):106-111. View Abstract
Darshan S. Doreswamy R. Patented antiinflammatory plant drug development from traditional medicine. Phytother.Res 2004;18(5):343-357. View Abstract
Eisen JS, Koren G, Juurlink DN, et al. N-acetylcysteine for the treatment of clove oil-induced fulminant hepatic failure. J Toxicol Clin Toxicol 2004;42(1):89-92. View Abstract
Elwakeel, H. A., Moneim, H. A., Farid, M., and Gohar, A. A. Clove oil cream: a new effective treatment for chronic anal fissure. Colorectal Dis. 2007;9(6):549-552. View Abstract
Jadhav BK, Khandelwal KR, Ketkar AR, et al. Formulation and evaluation of mucoadhesive tablets containing eugenol for the treatment of periodontal diseases. Drug Dev Ind Pharm 2004;30(2):195-203. View Abstract
Janes SE, Price CS, Thomas D. Essential oil poisoning: N-acetylcysteine for eugenol-induced hepatic failure and analysis of a national database. Eur J Pediatr 2005;164(8):520-2. View Abstract
Kim SI, Yi JH, Tak JH, et al. Acaricidal activity of plant essential oils against Dermanyssus gallinae (Acari: Dermanyssidae). Vet.Parasitol 4-15-2004;120(4):297-304. View Abstract
Li Y, Xu C, Zhang Q, et al. In vitro anti-Helicobacter pylori action of 30 Chinese herbal medicines used to treat ulcer diseases. J Ethnopharmacol 4-26-2005;98(3):329-333. View Abstract
Miyazawa M, Hisama M. Antimutagenic activity of phenylpropanoids from clove (Syzygium aromaticum). J Agric Food Chem 10-22-2003;51(22):6413-6422. View Abstract
Natural Standard Research Collaboration, Chief Editors: Ulbricht C, Basch E, Natural Standard Herb and Supplement Reference - Evidence-Based Clinical Reviews, USA: Elsevier/Mosby, 2005.
Somova LO, Nadar A, Rammanan P, et al. Cardiovascular, antihyperlipidemic and antioxidant effects of oleanolic and ursolic acids in experimental hypertension. Phytomedicine 2003;10(2-3):115-121. View Abstract
Taguchi Y, Ishibashi H, Takizawa T, et al. Protection of oral or intestinal candidiasis in mice by oral or intragastric administration of herbal food, clove (Syzygium aromaticum). Nippon Ishinkin Gakkai Zasshi 2005;46(1):27-33. View Abstract
Tajuddin A, Ahmad S, Latif A, et al. Aphrodisiac activity of 50% ethanolic extracts of Myristica fragrans Houtt. (nutmeg) and Syzygium aromaticum (L) Merr. & Perry. (clove) in male mice: a comparative study. BMC.Complement Altern Med 10-20-2003;3(1):6. View Abstract
Trongtokit Y, Rongsriyam Y, Komalamisra N, et al. Comparative repellency of 38 essential oils against mosquito bites. Phytother Res 2005;19(4):303-9. View Abstract
Copyright © 2013 Natural Standard (www.naturalstandard.com)
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.
March 22, 2017