Supplement
Clove is the dried flower bud of a tropical tree, and its main active compound, eugenol, numbs tissue and disrupts microbes. People mostly look at it for dental pain, and the evidence is moderate: small trials found a clove gel eased needle-stick pain in the mouth about as well as a common numbing gel. Most other claims, such as germ-killing or blood sugar effects, come from lab and animal work.
- Updated
- How we grade
- 25 studies cited
- Best evidence
- Grade B
- Conditions studied
- 3
- Outcomes
- 9
- Graded outcomes
- 0126
Evidence by condition
- Strong
- Moderate
- Limited
- Very limited
General
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Dental Pain Relief Eugenol from clove oil is FDA-approved as a dental analgesic for temporary toothache relief. Limited RCTs suggest topical clove gel has efficacy comparable to benzocaine 20% when applied to oral mucosa prior to needle insertion. Widely used in dental procedures as a component of zinc oxide-eugenol cements. | Improves (the measure goes down) | Moderate effect | 2 studies | 200 people | ||
Studies that measured dental pain relief | ||||||
| Antimicrobial Activity Extensive in vitro studies demonstrate broad-spectrum antimicrobial activity of clove oil and eugenol against gram-positive and gram-negative bacteria (including MDR A. baumannii and ESBL-producing strains), fungi (Candida, Fusarium), and oral pathogens. Mechanistic reviews attribute activity to eugenol-mediated membrane disruption and protein denaturation. No human clinical trials for systemic antimicrobial effects. | Changes; see studies | Moderate effect | 12 studies | |||
Studies that measured antimicrobial activity
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| Anti-inflammatory Effects In vitro studies show eugenol at noncytotoxic concentrations inhibits COX-2 and reduces pro-inflammatory cytokine production (TNF-α, IL-1β, IL-6) by murine macrophages. An in vivo animal study found clove essential oil nanogels produced significant anti-inflammatory and anti-nociceptive effects comparable to diclofenac. No human clinical trials for systemic anti-inflammatory use. | Changes; see studies | Small effect | 4 studies | |||
Studies that measured anti-inflammatory effects
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| Anticancer Properties In vitro studies demonstrate cytotoxic effects of clove extracts and eugenol against multiple cancer cell lines of various anatomical origins. Clove oil triggered apoptosis and cell cycle arrest in colon cancer (Caco-2) cells. A review of eugenol's anticancer mechanisms highlights induction of apoptosis, inhibition of proliferation, and anti-angiogenic effects. No human clinical trials. | Changes; see studies | Small effect | 4 studies | |||
Studies that measured anticancer properties
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| Immunomodulatory Effects In vitro studies show clove essential oil and constituents modulate both humoral and cell-mediated immune responses, affecting lymphocyte subtype expansion, cytokine profiles, and macrophage activation. Both aqueous and ethanolic extracts demonstrate dose-dependent immunomodulatory activity. No human clinical trials. | Improves (the measure goes up) | Small effect | 4 studies | |||
Studies that measured immunomodulatory effects
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| Blood Sugar Regulation Animal studies and small preliminary human observations suggest clove may help regulate blood glucose levels, potentially by enhancing insulin function or slowing carbohydrate digestion. Evidence remains preliminary with no well-powered human RCTs published. | Improves (the measure goes down) | Small effect | 1 study | |||
Cardiovascular Health
- Antiplatelet Activity: changes; see studies
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Antiplatelet Activity A single study identified antiplatelet principles from clove, showing eugenol and related compounds inhibit thromboxane synthesis and platelet aggregation via prostaglandin pathway modulation. No human clinical trials evaluating cardiovascular or anticoagulant effects. | Changes; see studies | Small effect | 2 studies | |||
Studies that measured antiplatelet activity | ||||||
Bone Health
- Bone Preservation: improves
| Grade | Outcome | Effect | Size | Studies | People | Studies list |
|---|---|---|---|---|---|---|
| Bone Preservation A single preclinical study found clove extract rich in eugenol and eugenol derivatives showed bone-preserving efficacy in an animal model of bone loss. The mechanism may involve antioxidant and anti-resorptive properties. No human clinical trials. | Improves (the measure goes up) | Small effect | 1 study | |||
Studies that measured bone preservation | ||||||
Key findings
- Dental Pain ReliefImproves (the measure goes down)
- Antimicrobial ActivityChanges; see studies
- Anti-inflammatory EffectsChanges; see studies
Studies cited
25 studies from PubMed
- Antibacterial, antioxidant, and cytotoxic activities of Syzygium aromaticum (L.) Merr. & Perry essential oil with identification of its chemical constituents.
- Anti-inflammatory and anti-nociceptive effects of Cinnamon and Clove essential oils nanogels: an in vivo study.
- Antioxidant-rich Clove Extract, A Strong Antimicrobial Agent against Urinary Tract Infections-causing Bacteria in vitro.
- Antibacterial activity of clove (Syzygium aromaticum) and cinnamon (Cinnamomum burmannii) essential oil against extended-spectrum β-lactamase-producing bacteria.
- Clove Essential Oil (Syzygium aromaticum L. Myrtaceae): Extraction, Chemical Composition, Food Applications, and Essential Bioactivity for Human Health.
- Anticancer Properties of Eugenol: A Review.
- Yield, Quality, and Antioxidant Activity of Clove (Syzygium aromaticum L.) Bud Oil at the Different Phenological Stages in Young and Mature Trees.
- Syzygium aromaticum (clove) and Thymus zygis (thyme) essential oils increase susceptibility to colistin in the nosocomial pathogens Acinetobacter baumannii and Klebsiella pneumoniae.
- Antimicrobial and antioxidant activity of unencapsulated and encapsulated clove (Syzygium aromaticum, L.) essential oil.
- Triggering of apoptosis and cell cycle arrest by fennel and clove oils in Caco-2 cells: the role of combination.
- Antifungal activities of selected essential oils against Fusarium oxysporum f. sp. lycopersici 1322, with emphasis on Syzygium aromaticum essential oil.
- Antimicrobial activity of eugenol and essential oils containing eugenol: A mechanistic viewpoint.
- Bactericidal activity of herbal volatile oil extracts against multidrug-resistant Acinetobacter baumannii.
- Antimicrobial and Virulence-Modulating Effects of Clove Essential Oil on the Foodborne Pathogen Campylobacter jejuni.
- Immunomodulatory effects of clove (Syzygium aromaticum) constituents on macrophages: in vitro evaluations of aqueous and ethanolic components.
- Anti-cholinesterase activity of the standardized extract of Syzygium aromaticum L.
- Clove (Syzygium aromaticum) ingredients affect lymphocyte subtypes expansion and cytokine profile responses: An in vitro evaluation.
- Bioactive lipids, radical scavenging potential, and antimicrobial properties of cold pressed clove (Syzygium aromaticum) oil.
- Clove (Syzygium aromaticum Linn) extract rich in eugenol and eugenol derivatives shows bone-preserving efficacy.
- Clove and eugenol in noncytotoxic concentrations exert immunomodulatory/anti-inflammatory action on cytokine production by murine macrophages.
- Comparative anticancer potential of clove (Syzygium aromaticum)--an Indian spice--against cancer cell lines of various anatomical origin.
- Immunomodulatory activity of Zingiber officinale Roscoe, Salvia officinalis L. and Syzygium aromaticum L. essential oils: evidence for humor- and cell-mediated responses.
- Antimicrobial activity of clove and rosemary essential oils alone and in combination.
- Cytotoxicity of clove (Syzygium aromaticum) oil and its major components to human skin cells.
- Antiplatelet principles from a food spice clove (Syzygium aromaticum L) [corrected].