Clove Side Effects: Dangers and Contraindications

Does clove cause side effects? At usual culinary doses (1 to 3 cloves a day), rarely, and only minor discomfort: mouth irritation, a local burning sensation, worsening of existing acidity. The serious point of caution concerns a very different, far more concentrated form: essential oil, for which a published clinical case precisely documents the liver risk of excessive ingestion, particularly in children.

This article details the known side effects, from the most common and mild to the rarest and most serious, with the scientific source behind each. For benefits and uses, see our fact sheet clove; for a broader view of risks and at-risk groups, our article clove dangers complements this page.

The most frequent side effects stay mild

• Mouth or digestive irritation: the most commonly reported, with overdosing of the spice — beyond a few cloves a day.
• Transient local burning sensation, if a whole clove is left against the gum too long.
• Worsening of acidity or reflux in people already sensitive: clove is a very warming spice, one that easily aggravates the Pitta dosha.
• Skin reactions with external use: rare irritation with essential oil applied without sufficient dilution.

For the vast majority of people consuming the whole spice at a moderate dose, these effects stay mild and reversible on stopping or lowering the dose.

The documented case: acute hepatitis after essential oil ingestion

This is the reference study on clove's serious toxicity. Janes, Price and Thomas, in a 2005 article published in the European Journal of Pediatrics, described the case of a 15-month-old boy who ingested about 10 ml of clove essential oil. The child developed fulminant acute liver failure, with transaminases (ALT) exceeding 13,000 U/l within 24 hours, along with associated kidney involvement. The clinical picture, close to that of an acetaminophen overdose, is explained by eugenol's toxicity mechanism, which depletes the liver's glutathione reserves at high dose. The good news: treatment with N-acetylcysteine (the antidote used for acetaminophen poisoning) led to gradual improvement in liver function within days (see the study on Google Scholar).

Three clarifications put this risk in perspective: this case, and others published in the literature, consistently involve ingestion of concentrated essential oil, not the whole spice used in cooking; the volumes involved (several milliliters) have nothing to do with a clove chewed or simmered into a dish; and the outcome, with appropriate treatment, was favorable. This warrants real caution around essential oil — particularly keeping it out of children's reach — not concern over the culinary spice.

Who should be especially cautious?

Situation	What the literature shows	What to do
Young children	Liver toxicity documented from just a few milliliters of ingested essential oil	Essential oil off-limits for children, kept systematically out of reach
Known liver disease	Eugenol's liver-toxicity mechanism identified at high dose	Avoid essential oil; moderate culinary spice has no specific warning signal
Anticoagulant treatment	Eugenol's platelet anti-aggregant effect shown in laboratory work	Report any significant, regular consumption to your doctor
Unusual symptoms after accidental ingestion	Intense fatigue, vomiting, altered consciousness: warning signs	Seek emergency care, contact a poison control center

Interactions and effect on clotting

Beyond the liver, eugenol has a platelet anti-aggregant effect shown by laboratory work on clove and its main compound: at high concentration, it slows platelet aggregation through a mechanism distinct from aspirin's. At culinary doses, this effect stays theoretical with no known consequence. It still justifies a simple precaution: people on anticoagulant treatment or preparing for surgery should report any significant clove consumption — spice or essential oil — to their doctor.

Pregnancy, breastfeeding and children: caution still applies

Culinary doses (a few cloves in a dish or drink) pose no known problem during pregnancy and breastfeeding, as detailed in our article clove and pregnancy. Essential oil, however, should be avoided entirely by pregnant or breastfeeding women, and even more so around children, where the clinical case above concretely illustrates the danger of accidental ingestion.

Whole spice or essential oil: keep the two clearly separate

Most concerns about clove's side effects come from confusing two very different products. The whole clove, used in cooking at a rate of 1 to 3 a day, releases a modest, gradual amount of eugenol. Essential oil concentrates this same compound at considerably higher levels: a few milliliters are enough to reach the doses linked to the serious cases published in the literature. If a healthcare professional or aromatherapist recommends its use, it should always be taken heavily diluted, never applied undiluted to skin or a mucous membrane, and never taken orally without precise dose supervision. It should be stored in a dropper bottle, out of children's reach, like any concentrated product that is potentially toxic.

When to seek care

Seek care without delay for essential oil ingestion by a child, even in a small amount, or for vomiting, intense fatigue or altered consciousness after significant exposure to clove in any form. Clove, whether spice or oil, never replaces prescribed treatment or medical advice. General safety guidelines for Ayurvedic herbs and essential oils are detailed in our safety and precautions guide.