Coriander (Cilantro) (Coriandrum sativum): Uses, Evidence and Safety

Safety first. Fresh cilantro leaves and coriander seeds are foods for most people. The sources we read raise these cautions. (1) Coriander is among the spices implicated in allergic reactions, which can range from mild mouth symptoms to anaphylaxis (a severe, life-threatening allergic reaction). [1] (2) LactMed reports that allergic reactions and photosensitivity (skin that reacts to sunlight) have been reported, and that coriander can cause contact dermatitis (a skin rash). [2] (3) A "cilantro detox" claim has no human evidence behind it that we could find (see the claim check below). For a severe allergic reaction, call 911.

What coriander is

Coriander and cilantro are both Coriandrum sativum L., accepted by GBIF in the family Apiaceae (the carrot and celery family). [3] LactMed lists both "Cilantro" and "Coriander" among the names for the plant [2] and describes the seeds as containing a volatile oil made mainly of linalool, which gives coriander its odor and taste. [2] Studies below tell you which part was used, because leaf, seed, seed powder and extract are not interchangeable. Cumin is a relative with its own page: Cumin.

Traditional use

This is tradition, not proof. LactMed says coriander is a purported galactogogue (a substance said to increase milk supply) and has been included in some mixtures promoted to increase milk supply, but no scientifically valid clinical trials support this use. [2] For coriander in Ayurvedic digestive teas, see Cumin, Coriander, Fennel, Ginger and Ayurvedic Digestive Teas. The sources we read do not name other peoples or practices, so we do not.

What research shows

We searched PubMed (2026-10-23) for Coriandrum sativum with randomized, systematic review and meta-analysis terms. Human trials were rare.

One small trial in people with diabetes cannot show that coriander helps blood sugar, and it says nothing about cilantro leaves in food.

Claim check: "Cilantro detoxes heavy metals"

The claim as marketed: eating cilantro or taking cilantro extracts pulls metals such as mercury or lead out of the body.

What the evidence is: Proper evidence not found. We searched PubMed (2026-10-23) for Coriandrum sativum and cilantro together with chelation, detoxification, heavy metal, mercury and lead terms. We found no human trial showing that cilantro removes metals from the body. The results we did find were about crops taking metals up.

What the research says instead: a 2021 systematic review and meta-analysis of 32 articles measured potentially harmful elements in the edible part of lettuce and coriander irrigated with wastewater, and concluded that wastewater reuse in agriculture can endanger consumers' health. [6] Coriander can therefore be a source of metals when it is grown in contaminated conditions, not only a remedy for them. The review covers wastewater-irrigated crops specifically and does not tell you about the cilantro in a given store or product.

What regulators say: none of the sources we read for this page is a regulator statement about cilantro. For how chelation and "heavy-metal detox" claims are assessed, see Liver Detox, Heavy-Metal Detox and Parasite Cleanse Claims Checked and Chelation Therapy: Legitimate Medical Uses vs Alternative Claims.

What a reader can safely do: if you are worried about lead, mercury or other exposure, ask a clinician about proper testing and treatment, and avoid substituting a supplement for care. For a suspected poisoning, call Poison Help at 1-800-222-1222 (US). Product contamination is covered at Product Quality and Contamination.

Why cilantro tastes like soap to some people

A 2026 structural study of the human olfactory receptor OR6A2 notes that it belongs to a cluster of receptors genetically associated with the "soapy" perception of cilantro. [7] That is a genetic difference in smell, not an allergy or a sign that the herb has gone bad. The abstract we read gives no figures on how common it is, so we do not state any.

Safety

• Allergy: a 1997 laboratory study found IgE antibodies in some patients' blood reacting to allergens in anise, fennel, coriander and cumin, which belong to the same plant family. [8] See Herbal Allergy and Cross-Reactivity.
• Breastfeeding and milk-supply products: LactMed reports one case of excessive use that possibly caused endocrine disruption in a nursing mother who drank a coriander water extract (about 10%) daily for a week to enhance her milk supply, with the extract's verification and possible contaminants not stated; and elevated liver enzymes in a woman taking a tea product that contains coriander. [2] These are single reports, and the second involved a product rather than coriander alone. LactMed says coriander is generally recognized as safe as a food. [2]
• Diabetes medicines (theoretical): no interaction is documented in the sources we read. Because a trial measured lower blood sugar, ask a pharmacist; see Herbs for Blood Sugar and Diabetes.
• Pregnancy, children, older adults, kidney disease, bleeding, surgery: not described in the sources we read. See Pregnancy and Breastfeeding.

We give no amounts to take; the trial amount above is that study's, not advice. A clinician or pharmacist decides what suits a person.