Clove (clove oil and clove bud extract)

Q: Does clove oil work for toothache?

In 73 adults, a homemade clove gel numbed the gum about as well as 20% benzocaine gel before a needle stick. That is a numbing test, not a toothache trial, and it does not replace dental care.

Q: Do clove supplements help with hangovers?

One crossover trial in 16 men found 55% lower hangover scores with 250 mg of a clove bud extract, but it was run by the extract's maker and has not been repeated.

Q: Does clove thin the blood?

Eugenol reduced platelet clumping in lab and mouse studies. Whether clove supplements affect bleeding in people has not been tested.

Q: Is it safe to swallow clove oil?

No for concentrated oil. NIH LiverTox says high-dose ingestion can cause severe liver injury, and swallowing under 8 ml or 10 ml caused liver failure in a 3-month-old and a 15-month-old.

Q: How much clove oil is dangerous to swallow?

LiverTox describes overdoses after swallowing about 10–30 mL of clove oil, with coma, low blood sugar and liver failure. In young children, less than 8 mL (a 3-month-old) and 10 mL (a 15-month-old) caused acute liver failure.

Q: What are the side effects of clove oil?

On the skin or gums, LiverTox notes few side effects beyond local irritation, rare allergic reactions and contact dermatitis. Swallowing large amounts can cause seizures, coma, low blood sugar and liver failure, mostly reported in young children.

Q: Is clove mouthwash better than chlorhexidine?

One trial in 168 ventilated ICU patients found half the pneumonia rate with a 6.66% clove mouthwash. It is a single hospital study of a clinical product.

Also called cloves, Syzygium aromaticum, Eugenia caryophyllata, clove oil, clove bud oil, eugenol.

Best grade C across 5 graded outcomes Botanical Last checked Oct 21, 2026

The short answer

From 13 sources

Most clove trials apply it to the skin, gums or mouth. A homemade clove gel matched benzocaine for needle-stick pain, and a clove mouthwash beat chlorhexidine for ventilator pneumonia in one trial. Two oral extract studies had 16 and 13 people and were run by the extract's maker. Swallowing clove oil can cause severe liver injury.

Every graded outcome on this page

5 rows · line = participants

Grade CVentilator-associated pneumonia in ICU patientsICU mouth caren 168
Grade CNeedle-stick pain on the gum after a topical gelDental numbingn 73
Grade DChronic anal fissure closure at 3 monthsAnal fissuren 55
Grade DHangover severity and blood markers after heavy drinkingHangovern 16
Grade DBlood glucose before and after mealsBlood sugarn 13
2 more graded outcomes, in the evidence chapter

Key facts

Gum numbing: Clove gel and 20% benzocaine gel both lowered needle-stick pain versus placebo in 73 adults, with no difference between them¹
ICU mouthwash: 20.2% vs 41.7% of ventilated ICU patients developed pneumonia with clove mouthwash vs chlorhexidine (168 patients)³
Oral supplement: Two small trials of 250 mg/day clove bud polyphenol extracts, both by the manufacturer: a 16-person hangover crossover and a 13-person open-label blood-sugar pilot^4,12
Clove oil overdose: NIH LiverTox likelihood score C[H] (probable cause of liver injury in overdoses): normal doses are not linked to liver injury, but swallowing large amounts, typically 10–30 mL, can cause severe liver injury⁶
Children: Swallowing under 8 ml of clove oil (a 3-month-old) or 10 ml (a 15-month-old) caused acute liver failure; both recovered after N-acetylcysteine treatment^7,8

What it is

Clove is the dried flower bud of Syzygium aromaticum. Its oil is mostly eugenol and is used in dentistry; oral extracts are sold as supplements.

How it works

Proposed

Eugenol is the main phenolic compound in clove oil. Trials tested clove gel as a topical anaesthetic for the gum, and the Clovinol trial authors attribute their results to antioxidant clove polyphenols. Lab and animal studies, summarised in a 2025 review, report that eugenol reduces platelet clumping. None of these mechanisms are confirmed in people taking oral supplements.^11,1,4,10

Forms, side by side

3 forms named in our sources. The rest show what our data holds, and say plainly where it holds nothing yet.

Clove (clove oil and clove bud extract) forms compared

3 forms

Clove (clove oil and clove bud extract) forms compared: 3 forms by 3 attributes. Empty cells are labelled No data yet, or Not graded in the evidence row.
3 forms	Clove oil (eugenol-rich essential oil)	Clove extract mouthwash	Clove bud polyphenol extract (Clovinol)
Absorption in people	Not measured in the cited trials; eugenol alone at 150 mg/day for 7 days caused no blood chemistry changes in 10 men.^2,5,6	Not systemically measured in the trial abstract.³	Not reported in the abstract.⁴
GI tolerance	Swallowed clove oil can cause severe liver injury; NIH LiverTox links liver injury to high-dose ingestion, not normal use.^2,5,6	Not described in the abstract.³	Not described in detail in the abstract.⁴
Studied for	Topical creams, gum gels, dental use	ICU mouth care	Blood markers after heavy drinking; a related water-soluble bud extract was tested for blood glucose (open-label pilot)

Clove oil (eugenol-rich essential oil)
Absorption in people
Not measured in the cited trials; eugenol alone at 150 mg/day for 7 days caused no blood chemistry changes in 10 men.^2,5,6
GI tolerance
Swallowed clove oil can cause severe liver injury; NIH LiverTox links liver injury to high-dose ingestion, not normal use.^2,5,6
Studied for
Topical creams, gum gels, dental use
Clove extract mouthwash
Absorption in people
Not systemically measured in the trial abstract.³
GI tolerance
Not described in the abstract.³
Studied for
ICU mouth care
Clove bud polyphenol extract (Clovinol)
Absorption in people
Not reported in the abstract.⁴
GI tolerance
Not described in detail in the abstract.⁴
Studied for
Blood markers after heavy drinking; a related water-soluble bud extract was tested for blood glucose (open-label pilot)

What the human research says

Human trials only, one row per outcome. The form line shows what each trial actually tested. Grades follow our evidence-grading policy.

Trial map

5 graded outcomes, largest study first

All 5 graded outcomes found an improvement. The largest, a 2023 randomized trial of 168 people on Ventilator-associated pneumonia in ICU patients, found an improvement.

By sizeTable

1Ventilator-associated pneumonia in ICU patients

Improved · Grade C · RCT, 168 people, 2023

Ventilated ICU patients in Iran

Dose, result and source

Every graded outcome on this page, largest study first
Outcome	Found	People	Study	Who was studied
Ventilator-associated pneumonia in ICU patients	Improved	168	Grade C · RCT, 2023	Ventilated ICU patients in Iran
Needle-stick pain on the gum after a topical gel	Improved	73	Grade C · RCT, 2006	Adult volunteers
Chronic anal fissure closure at 3 months	Improved	55	Grade D · RCT, 2007	Adults with chronic anal fissure
Hangover severity and blood markers after heavy drinking	Improved	16	Grade D · Crossover RCT, 2018	Male social drinkers
Blood glucose before and after meals	Improved	13	Grade D · Open-label trial, 2019	Otherwise healthy adults with normal or raised fasting glucose

Every graded row

5 rows

Form tested

Showing 5 of 5 outcomes. Human trials only.

Grade CVentilator-associated pneumonia in ICU patientsICU mouth careHalf the pneumonia rateRCT
n 168 · 2023

Improved 20.2% of the clove group and 41.7% of the chlorhexidine group developed pneumonia (RR 2.06 for control, 95% CI 1.26-3.37, p = 0.005); pneumonia severity did not differ.

Design: RCT, n = 168, 2023
Population: Ventilated ICU patients in Iran
Form: Clove extract mouthwash 6.66% vs chlorhexidine 0.2%
Dose: Twice daily
Duration: 5 days
Source: Reference 3 · PubMed 36961592 (opens PubMed)

Grade CNeedle-stick pain on the gum after a topical gelDental numbingSimilar to benzocaineRCT
n 73 · 2006

Improved Clove and benzocaine gels both gave lower mean pain scores than placebos (p = 0.005); clove and benzocaine did not differ.

Design: RCT, n = 73, 2006
Population: Adult volunteers
Form: Homemade clove gel vs 20% benzocaine gel and matching placebos, applied to the gum for 5 minutes
Dose: Single application
Duration: Single session
Source: Reference 1 · PubMed 16530911 (opens PubMed)

Grade DChronic anal fissure closure at 3 monthsAnal fissure60% vs 12% closedRCT
n 55 · 2007

Improved Healing occurred in 60% of the clove oil group vs 12% of controls at 3 months (P < 0.001); resting anal pressure fell more with clove oil.

Design: RCT, n = 55, 2007
Population: Adults with chronic anal fissure
Form: Clove oil 1% cream vs stool softeners plus lignocaine 5% cream
Dose: Topical cream
Duration: 6 weeks (3-month follow-up)
Source: Reference 2 · PubMed 17573751 (opens PubMed)

Grade DHangover severity and blood markers after heavy drinkingHangover55% lower hangover scoreCrossover RCT
n 16 · 2018

Improved Blood acetaldehyde cleared faster and oxidative stress, CRP and interleukin-6 fell versus placebo; hangover severity scores were 55.34% lower.

Design: Crossover RCT, n = 16, 2018
Population: Male social drinkers
Form: Clove bud polyphenol extract (Clovinol) vs placebo
Dose: 250 mg/day
Duration: Not clearly stated; blood sampled over 12 hours after drinking in each arm (2-week washout)
Source: Reference 4 · PubMed 30234415 (opens PubMed)

Grade DBlood glucose before and after mealsBlood sugarImprovedOpen-label trial
n 13 · 2019

Improved Two-hour post-meal glucose fell from baseline by day 12 (by 13.3 mg/dL with normal and 16.7 mg/dL with raised fasting glucose) and stayed lower through day 30; fasting glucose fell only in the raised-glucose group (by 13.7 mg/dL at day 30).

Design: Open-label trial, n = 13, 2019
Population: Otherwise healthy adults with normal or raised fasting glucose
Form: Water-soluble clove bud polyphenol extract
Dose: 250 mg once daily
Duration: 30 days
Source: Reference 12 · PubMed 31064377 (opens PubMed)

What the numbers add up to

Each point is worked out from the data and the sources numbered on this page, with the arithmetic shown under it. It adds no new data and is not medical advice.

A topical herb more than a supplement

Three of the five studies on this page applied clove to the gum, skin or mouth. The two that tested a swallowed clove supplement had 16 and 13 people and were run by the extract's maker.^1,2,3,4,12

Safety data come from poisonings

The clearest human data on swallowed clove oil are case reports of liver failure in children, while a 7-day eugenol study in 10 men found no blood chemistry changes at 150 mg/day.^7,8,5

Studied doses

Doses used in research, shown against the official limits. They describe the studies, not a recommendation for you.

Studied doses in research, not advice. These are amounts used in research, not personal advice. Your clinician or pharmacist can say what fits you.

Doses studied in human trials

Doses studied in human trials ranged from 150 mg/day of pure eugenol for 7 days (a safety study) to 250 mg/day of clove bud polyphenol extracts, used around a drinking session and for 30 days in a blood-sugar pilot. Most clove trials used creams, gels or mouthwash rather than swallowed doses. These are research doses, not recommendations.^5,4,12

When trials measured an effect

2 outcomes

How long trials ran before effects were measured
Outcome	Measured at	Basis
After-meal blood glucose	Day 12, sustained to day 30	Open-label pilot of 250 mg/day clove bud extract in 13 adults; no control group¹²
Gum numbing before a needle stick	After a 5-minute application	Clove gel applied to the gum for 5 minutes before the needle stick, versus benzocaine and placebo¹

Interactions and safety

Published interactions only: each row cites a source. No row means none was found in our sources, not that a combination is safe.

What Clove meets

1 cited row

Medicines 1

Clove1 medicine · 0 supplements

Supplements and foods 0

No supplement rows in our sources.

Reference summary

Interactions

1 agent

Published interactions, grouped by kind
Agent	What the source says	Evidence
Medicines1
Anticoagulant and antiplatelet drugse.g. warfarin, clopidogrel, aspirin (inferred from mechanism)	A 2025 review notes that eugenol inhibits platelet aggregation, and it reduced collagen- and arachidonic acid-induced aggregation of human platelets in the lab. No clinical interaction study exists, so this is a theoretical concern.^11,10	Review

Check with what you take

Kept on this device only

Add what you take. We list every interaction our evidence profiles cite between Clove and your picks, and between your picks.

Add a supplement or medicine

Most cited:

Add a supplement or medicine you take to check it against Clove.

Starting from one medicine? The interaction checker rates how serious each pair is, on a curated list of 19 entries for 11 medicines. This cabinet has no severity rating: it lists every interaction row our supplement pages cite.

Who should be careful

4 groups

Young children: Swallowing under 8 ml of clove oil caused liver failure in a 3-month-old and 10 ml did so in a 15-month-old; another child developed blood-clotting failure (DIC) and liver necrosis. Keep clove oil out of children's reach.^7,8,9
Anyone thinking of swallowing clove oil: NIH LiverTox gives eugenol likelihood score C[H], a probable cause of liver injury in overdose: swallowing large amounts (typically 10–30 mL of clove oil) caused coma, low blood sugar and acute liver failure within a day, mostly in children. Normal food and topical amounts have not been linked to liver injury. The cited trials applied the oil to skin or gums.⁶
People with bleeding risk or before surgery: Eugenol reduced platelet clumping in lab studies; effects in people on blood thinners have not been tested.^11,10
Pregnancy and breastfeeding: No reliable data. None of the cited trials enrolled pregnant or breastfeeding women, and LactMed has no clove entry. Clove as a cooking spice is common; the documented harms come from swallowing concentrated clove oil.^1,4,12,6

How to read the label

What to check on the Supplement Facts panel.

How to read the label

2 checks

Oil vs extract

Clove oil is concentrated eugenol. Clove bud polyphenol extracts such as Clovinol are a different product, and the 250 mg/day trial used that extract, not the oil.^4,6

Topical percentages

Trials used a 1% clove oil cream and a 6.66% clove extract mouthwash; neat clove oil is far stronger than either.^2,3

Have the bottle? Photograph its Supplement Facts panel and see each line, clove (clove oil and clove bud extract) included, beside the doses and forms the trials used in Label X-Ray.

Frequently asked questions

Short answers to common questions; the numbers link to the sources below.

Common questions

7 answers

Does clove oil work for toothache?

In 73 adults, a homemade clove gel numbed the gum about as well as 20% benzocaine gel before a needle stick. That is a numbing test, not a toothache trial, and it does not replace dental care.¹

Do clove supplements help with hangovers?

One crossover trial in 16 men found 55% lower hangover scores with 250 mg of a clove bud extract, but it was run by the extract's maker and has not been repeated.⁴

Does clove thin the blood?

Eugenol reduced platelet clumping in lab and mouse studies. Whether clove supplements affect bleeding in people has not been tested.^11,10

Is it safe to swallow clove oil?

No for concentrated oil. NIH LiverTox says high-dose ingestion can cause severe liver injury, and swallowing under 8 ml or 10 ml caused liver failure in a 3-month-old and a 15-month-old.^6,7,8

How much clove oil is dangerous to swallow?

LiverTox describes overdoses after swallowing about 10–30 mL of clove oil, with coma, low blood sugar and liver failure. In young children, less than 8 mL (a 3-month-old) and 10 mL (a 15-month-old) caused acute liver failure.^6,7,8

What are the side effects of clove oil?

On the skin or gums, LiverTox notes few side effects beyond local irritation, rare allergic reactions and contact dermatitis. Swallowing large amounts can cause seizures, coma, low blood sugar and liver failure, mostly reported in young children.^6,7,8

Is clove mouthwash better than chlorhexidine?

One trial in 168 ventilated ICU patients found half the pneumonia rate with a 6.66% clove mouthwash. It is a single hospital study of a clinical product.³

Sources

13 sources: trial abstracts, NIH fact sheets and reference databases. Numbers in the text link here.

Sources cited on this page

13 sources

1The effect of clove and benzocaine versus placebo as topical anesthetics.RCT J Dent, 2006 · PMID 16530911
2Clove oil cream: a new effective treatment for chronic anal fissure.RCT Colorectal Dis, 2007 · PMID 17573751
3Effect of clove mouthwash on the incidence of ventilator-associated pneumonia in intensive care unit patients: a comparative randomized triple-blind clinical trial.RCT Clin Oral Investig, 2023 · PMID 36961592
4Clove Bud Polyphenols Alleviate Alterations in Inflammation and Oxidative Stress Markers Associated with Binge Drinking: A Randomized Double-Blinded Placebo-Controlled Crossover Study.Crossover RCT J Med Food, 2018 · PMID 30234415
5Effect of short-term dietary administration of eugenol in humans.Crossover RCT Hum Exp Toxicol, 1996 · PMID 8645503
6Eugenol (Clove Oil).Database 2012 · PMID 31869191
7Essential oil poisoning: N-acetylcysteine for eugenol-induced hepatic failure and analysis of a national database.Observational Eur J Pediatr, 2005 · PMID 15895251
8N-acetylcysteine for the treatment of clove oil-induced fulminant hepatic failure.Observational J Toxicol Clin Toxicol, 2004 · PMID 15083943
9Disseminated intravascular coagulation and hepatocellular necrosis due to clove oil.Observational Blood Coagul Fibrinolysis, 1992 · PMID 1450336
10Eugenol Suppresses Platelet Activation and Mitigates Pulmonary Thromboembolism in Humans and Murine Models.Animal study Int J Mol Sci, 2024 · PMID 38396774
11Cardiovascular protective properties of the natural product eugenol.Review Eur J Pharmacol, 2025 · PMID 40623537
12Water-soluble polyphenol-rich clove extract lowers pre- and post-prandial blood glucose levels in healthy and prediabetic volunteers: an open label pilot study.Open-label trial BMC Complement Altern Med, 2019 · PMID 31064377
13Comparative Evaluation of Pain Perception Following Topical Application of Clove Oil, EMLA 5%, and Lignocaine Hydrochloride Gel 2% as a Pre-anesthetic Agent in Children Aged 7-10 Years: A Randomized Controlled Study.RCT Int J Clin Pediatr Dent, 2026 · PMID 42582221

What changed

Every dated change to this page: what changed, who made it and why.

Change log

3 entries

Dated changes to this page
Date	Change	Who and why
Oct 21, 2026summary, evidence, key facts, who should avoid, FAQ, questions, time to effect, studied doses, related	Added the LiverTox likelihood score (C[H], probable cause of liver injury in overdose, typically after 10–30 mL) to the liver note and key facts, a 13-person open-label blood-sugar pilot of a clove bud extract (grade D, manufacturer-run), and a 2026 trial in 48 children comparing clove oil with EMLA and lidocaine before dental injections (row notes; n from full text). Rewrote the pregnancy and breastfeeding note as no reliable data (no LactMed entry), added FAQ on toxic amounts and side effects, page questions, time-to-effect rows and a goal-hub link, and updated the summary and insight to count both oral studies. Searched PubMed for clove, Syzygium aromaticum and eugenol trials and meta-analyses from 2018 to 2026; no meta-analysis of clove itself was found. Interactions: checked LiverTox and LactMed (no clove entry); no new interactions beyond the existing antiplatelet note.	Writer: Kymata Health EditorialTrigger: A–Z audit against docs/supplements/AUDIT-STANDARD.md
Oct 14, 2026all	Initial editorial evidence review (first draft). Every PMID checked against NCBI E-utilities esummary (titles and years taken from the record, none retracted) and the abstract read for each cited row. Studied doses are reported as research doses, not dosing advice.	Writer: Kymata Health EditorialTrigger: new page
Oct 14, 2026all	Adversarial review: corrected the infant clove-oil amounts (the 3-month-old swallowed under 8 ml per PMID 15083943; the 15-month-old 10 ml per PMID 15895251), replacing the inaccurate '8 to 10 ml' range.	Writer: Kymata Health EditorialTrigger: adversarial review

Supplement & Nutrient Encyclopedia. Educational information only; it is not medical advice and does not replace a clinician. Dietary supplements are not intended to diagnose, treat, cure or prevent any disease. Statements about supplements have not been evaluated by the FDA.

Clove (clove oil and clove bud extract)

Medicines 1

Supplements and foods 0

Anticoagulant and antiplatelet drugs