Syzygium aromaticum
Clove
Generally recognised as safeOther names: Eugenia caryophyllata
An Indonesian tree whose dried unopened buds become the spice clove.
A slender evergreen tree with opposite glossy leaves and buds borne in terminal clusters; the dried unopened buds are the fragrant cloves with a warm pungent flavor, a key spice and an essential-oil source.
- Family
- Myrtaceae
- Plant type
- Evergreen tree
What the safety levels mean (expand legend)
- Generally recognised as safe. Often a common herb with reasonable harvest and use; still read the specific warnings on the card.
- Information. Primarily informational — details in the text and warnings below matter most.
- Caution. Needs extra care (dose, duration, sensitive groups, interactions).
- Risky. Significant risks — verify sources, contraindications and professional guidance.
- Not for home experimentation. Not suitable to experiment with at home without knowledge and certainty.
- High risk for internal use. Particular risk with internal use (e.g. alkaloids); avoid prolonged or irresponsible dosing.
- Not specified. Level not filled in yet — rely on individual warnings and links below.
Photograph on Wikimedia Commons (CC BY-SA 4.0).
Plant habit
Safety — read before use
For this herb it is important to check warnings, mix-ups and cautions. Start with the Safety section.
Quick overview
A practical summary; details are in the sections below.
- Safety grade
- Generally recognised as safe details
- Scientific sources on the card
- Yes — sources are listed with claims Science section
- When and what to harvest
- Flower — July–October
- Processing methods
Herbal infusion (tea), Culinary use, Tincture, Essential oil
All methods and recipes on the card- Topics and symptoms
Digestion, Mouth and gums
Topics section, Symptoms overview
Identification and mix-ups
Evergreen tree in Myrtaceae reaching 8–20 m, with a dense pyramidal crown. Leaves opposite, leathery, glossy, ovate-lanceolate (8–13 cm), aromatic, with pink-red new growth. Flowers in terminal cyme-like panicles; the cylindrical calyx ripens from pale green to red-pink. The spice itself consists of the unopened flower buds, picked before the petals open. Fruit an ellipsoid one-seeded drupe ripening from red to dark purple.
Possible mix-ups and risks
No well-documented toxic lookalike exists for this species. The genus Syzygium (over 1000 species) is hard to distinguish, so non-spice members of the genus may appear in trade; the diagnostic character is always the unopened flower bud. The real-world risk is therefore not confusion with a poisonous plant but adulteration (bud stalks, exhausted buds, cheap clove-leaf oil).
Similar herbs
- Allspice
Clove and allspice smell alike because both contain eugenol. Cloves are dried buds with a head on a stalk, allspice round brown berries; the plants belong to different families.
Topics and symptoms
More topics are in the symptoms and topics overview.
- DigestionTraditional· Traditional / cultural framing
- Mouth and gumsTraditional· Traditional / cultural framing
Sources
Geographic occurrence
Indonesia
Common (expected wild occurrence in the region)
Harvest
- FlowerJuly–October
summer
Region: IndonesiaNotes: Unopened buds at the pink stage; sun-dried to a brown colour.
Storage
- Airtight storage(Flower)
Whole buds keep 2–3 years in an airtight jar; good cloves release a drop of oil when pressed with a fingernail and float head-up in water. Ground clove loses strength within six months.
- Light:
- Out of light.
- Moisture:
- Protect from moisture.
- Safety:
- Keep clove oil out of children's reach — even a small amount swallowed by a child is dangerous.
Processing methods on this herb card
Infusion or brief extraction in hot water; usually without long boiling.
Full method description (from the catalogue)
Here, herbal tea is prepared as an infusion: pour freshly boiling water over dried herbs or a herbal blend and steep for at least 5 minutes. BfR gives this as a hygiene rule, not a medicinal dose. Follow the specific product instructions, including a longer steeping time when stated. This rule for herbal infusions is not a general preparation guide for true tea (Camellia sinensis). Temperature, steep time, and the herb-to-water ratio change both flavour and what dissolves into the liquid.
Compared with a decoction, heat exposure is shorter and gentler; tender leaves and flowers are often better as an infusion than with prolonged simmering. For each herb, always follow the plant card for suitable plant part, preparation, and safety notes — general rules never replace species-level judgement.
Traditional context for this method: yes·Scientific context for this method: yes
Cooking, baking, seasoning as food — general category without therapeutic claims.
Full method description (from the catalogue)
Culinary use covers herbs as ingredients in dishes, drinks, or spice mixes. This overview does not evaluate medicinal effects — only reminds you about species intent, allergies, and heat treatment where needed (e.g. some fruits or plant parts).
Combining with alcohol, sugar, or long cooking changes outcomes; verify culinary sources.
Traditional context for this method: yes·Scientific context for this method: no
Alcoholic or alcohol–water maceration extract.
Full method description (from the catalogue)
A tincture is usually a long maceration of plant material in ethanol (sometimes with water). Alcohol and time release different compound groups than hot water alone; concentration and stability depend on the herb-to-solvent ratio and procedure.
Home production involves legal and safety limits that vary by country; this site gives a general overview, not a recipe. For each herb, read the card for interactions and warnings before preparing anything yourself.
Traditional context for this method: yes·Scientific context for this method: no
A concentrated aromatic plant product; use depends on the specific product.
Full method description (from the catalogue)
Essential oil is a concentrated plant product obtained, for example, by steam distillation or pressing. A general drop count or dilution ratio does not establish safe use.
Choose a finished product intended for your purpose and follow its directions. Do not apply it to skin or swallow it unless the manufacturer explicitly allows that use. This overview is not a recipe for home dilution.
Traditional context for this method: yes·Scientific context for this method: yes
The eugenol-rich oil is used in dentistry and, per EMA HMPC, traditionally in the mouth — always by the drop and diluted. Ingestion of even a few millilitres by a child caused coma, seizures, coagulopathy and acute liver damage (Hartnoll et al. 1993). Close the bottle and keep it out of children's reach.
Traditional / spiritual use
Kept separate from science — entries are cultural or symbolic, not medical advice.
Sweet breath before the emperor, and clove cigarettes
General
Historical mentionFolk useHerbal loreRitualUnder the Han dynasty courtiers had to chew cloves before speaking with the emperor so their breath was fresh — one of the oldest records of the spice trade from the Moluccas to China. On Ternate and Tidore, the 'spice islands', a clove tree was planted for every child born and its health was tied to the child's fate; in the 16th and 17th centuries the Portuguese, Spanish and Dutch fought over the islands. In Indonesia cloves remain the base of kretek cigarettes, named after their crackle. A historical note and record of tradition.
- Form:
- cloves before the emperor, Spice Islands and kretek
- Claim strength:
- Historical mention
- Source note:
- Cortés-Rojas DF et al. (2014), Asian Pac J Trop Biomed 4:90–96 (historical introduction); Ternate and Tidore tradition; history of kretek (Kudus, 1880).
Scientific notes
Each claim lists a study type and a source (URL or DOI) where available. Dose notes from the literature are informational only.
How to read evidence strength and study type labels
Labels summarise how the catalogue entry is tagged — they are not a medical verdict on efficacy. For every row, read the summary, limitations and source link.
Evidence strength
- Evidence level not specified
- The author did not grade the record; judge from the summary, limitations and source link.
- Narrative / orientational literature
- Descriptive or expert literature without controlled group comparison — context rather than proof of effect.
- Weak evidence
- Study or conclusion with major methodological limits; treat only as a pointer for further reading.
- Preliminary findings
- First or smaller studies — interesting direction, not the final word on efficacy or safety.
- Moderate strength of evidence
- Moderate strength by study design; sample and context limits still apply.
- Stronger evidence
- Stronger design or consistency of results within the study's stated limits.
- Review article
- A review summarises multiple sources; quality depends on review method and field.
Study type
- Narrative / expert text
- Expert text or overview without a classical study design.
- In vitro study
- Cell culture or test-tube experiment — does not show an effect in the body.
- Animal study
- Animal model — transfer to humans is not automatic.
- Observational study
- Observing groups without random treatment assignment; confounding is possible.
- Clinical trial
- Human clinical trial; sample size and control group matter.
- Randomised controlled trial
- Randomised controlled trials are among the stronger designs when well conducted.
- Review study
- A review aggregates multiple papers — quality depends on selection rules.
- Systematic review
- Systematic review with explicit search and selection methodology.
- Meta-analysis
- Statistical pooling of studies; outcome depends on input data and heterogeneity.
- Regulatory assessment / monograph (EMA, WHO…)
- Regulatory body summary for a herbal product — different context from a single RCT; often about products, not home tea.
- Expert monograph (herbal preparations)
- Structured literature summary for a plant or drug — quality depends on author and edition year.
The EMA HMPC monograph for clove describes traditional use in oral hygiene — local analgesia for toothache.
Review articleRegulatory assessment / monograph (EMA, WHO…)Year: 2011Preparation form in the study: essential oil (topical)
Active compound / focus: eugenol (75–85% of the essential oil)
Limitations: Topical use in adults; always dilute the essential oil in a carrier and use short-term.
Dose note (from literature): See the PDF for preparations.
The review summarises the composition of clove (an oil with 70–90 % eugenol, eugenyl acetate, beta-caryophyllene) and laboratory data on antimicrobial, antioxidant, anaesthetic and insecticidal activity; clinical trials are rare and mostly dental.
Narrative / orientational literatureReview studyYear: 2014Limitations: Mostly preclinical data; a journal with weaker quality control.
Cortés-Rojas DF, de Souza CRF, Oliveira WP — Asian Pacific Journal of Tropical Biomedicine
Images
The main photo is in the card header. More images will appear here when available.
Safety
What the warning types mean
The type on each warning helps group themes — it does not replace the separate severity badge.
- Internal use
- Risks from swallowing, extracts, duration of use or concentration for internal use.
- Interactions / medicines
- Possible effect on medicines or concurrent treatment — check sources and a professional.
- Raw plant parts
- Raw, unripe or poorly prepared plant parts can be dangerous.
- Toxins and regulation
- Toxic constituents or regulated compounds (e.g. in distillates).
- Contact with the plant
- Skin or mucosa irritation from contact with fresh plant or sap.
- Allergy
- Allergic reactions, often linked to family sensitisation.
- Harvesting and contamination
- Contamination, species mix-ups or harvesting from unsuitable places.
- High doses of clove oilModerate severityInternal use
High oral doses of eugenol may stress the liver; always dilute the essential oil in a carrier and consult on use with anticoagulants.
- Ingestion of clove oil by a childHigh severityToxins and regulation
Hartnoll et al. 1993 (Archives of Disease in Childhood) described a child who, after swallowing clove oil, fell into a coma with seizures, a coagulopathy and acute liver damage — a picture resembling a severe paracetamol overdose. Store the oil closed and out of children's reach; if swallowed, call a poison centre at once.