cilantro

What is cilantro?

Cilantro is the fresh leaf and soft stem of Coriandrum sativum. The dried seed of the same plant is sold as coriander. In Latin American cooking the leaf is a staple, used raw in salsa, ceviche, soups and stews.

Most people meet it as food, not as medicine. Folk use in Mexico and Central America also treated it as a stomach-settling herb and a calming tea. Sellers now market it online as a way to clear heavy metals from the body.

The honest verdict: as a food, cilantro is safe for nearly everyone and adds vitamin K and plant antioxidants. As a remedy, human evidence is thin, and the heavy-metal claims are not backed by good trials. Long use in a tradition is not proof that a plant works, and it is not proof that it is safe.

How does cilantro work?

No one has shown clearly how cilantro leaf acts as a medicine in people.

In lab tests, the oils in the leaf slow the growth of some bacteria and fungi. Whether that happens in your gut after a meal is not known.

In animal studies, coriander extracts lowered blood sugar and blood fats. The doses were far larger than a plate of salsa. Good human trials have not confirmed the same effect.

The detox idea rests mainly on animal work. In mice, a cilantro extract reduced how much lead built up in bone. That is a long way from showing that eating the herb pulls metals out of a person.

Some of the calming use may be simple. A warm drink and a quiet pause settle the stomach on their own.

What forms does cilantro come in?

Fresh bunches from a grocer or market are the usual form.

- Fresh leaf and stem, raw or stirred in at the end of cooking - Frozen leaf or paste cubes, used like fresh - Dried leaf, which loses most of its smell and taste - Fresh juice, or leaves blended into drinks and smoothies - Capsules and tinctures made from leaf extract - Detox blends that pair cilantro with chlorella - Essential oil, which is very strong and meant for scent or flavouring only

Heat drives off the fresh flavour, so cooks add the leaf late. Supplements vary a lot in strength. They are not checked the way medicines are.

Where it comes from:

Coriander reached the Americas with Spanish and Portuguese settlers in the 1500s. Cooks folded the leaf into local dishes. It became a marker of Mexican, Peruvian, Colombian and Caribbean food.

Home healers in the region used it beyond the kitchen. Agua de cilantro and leaf teas were given for upset stomach, gas and restless sleep. Healers working in curanderismo also used it in cooling mixes for fevers and hot, itchy skin.

The plant is far older than that. Seeds were used for digestion around the Mediterranean, the Middle East and South Asia for thousands of years. This page describes what was done in the past, not what you should do at home.

What does cilantro help with?

• Gas, bloating and mild indigestion: This is the oldest and most common folk use of the plant. Latin American homes served leaf tea or agua de cilantro after heavy meals. The human trials that exist used coriander seed, not the leaf. A few small studies in people with irritable bowel syndrome found less pain and bloating with seed-based mixes. Those mixes held other herbs too, so the credit cannot be given to coriander alone. For the fresh leaf, there is no good human trial. If it helps you, the effect is likely mild.
• Poor appetite: Tradition treated the smell and taste as an appetite trigger. Bitter and aromatic herbs have been used this way in many cuisines. No human trial has tested cilantro leaf for appetite. Any benefit is likely about making food taste better, which is a real and ordinary thing.
• Trouble winding down at night: Evening leaf teas were a home remedy for nerves and poor sleep. In animal studies, linalool and coriander extracts had calming effects. Those doses were much higher than a cup of tea. No human sleep trial supports the leaf. Treat it as a pleasant drink, not as a sleep treatment.
• Claimed removal of heavy metals such as lead and mercury: This claim is popular online and is not supported by good human evidence. Take it seriously only as a warning sign about the seller. The claim traces back to animal work and to one small, poorly reported human case series. In mice, a cilantro extract cut lead build-up in bone. Lead and mercury poisoning are medical emergencies with real tests and real treatments. Do not delay care to try an herb.
• Blood sugar and blood fats: Animal studies using coriander seed extract showed lower blood sugar and lower cholesterol. The doses were far above food levels. Human trials are few, small and mostly on the seed. Results have been mixed and short-term. There is no basis for using cilantro in place of diabetes medicine.
• Keeping food fresh and limiting bacteria: In lab tests, cilantro oil and leaf extracts slow bacteria such as Salmonella and Listeria. Food scientists study it as a natural preservative. This does not mean a sprinkle of leaf makes risky food safe. Raw cilantro has itself been traced to outbreaks when grown or washed in dirty water. Wash fresh bunches well under running water.

Which foods are rich in cilantro?

1. Fresh cilantro bunches
2. Pico de gallo and salsa verde
3. Guacamole
4. Ceviche
5. Pozole and sopa de lima
6. Tacos and tortas with fresh herb garnish
7. Arroz con pollo and sofrito bases
8. Chutneys and fresh herb sauces

Practical Tips:

Cilantro is at its strongest raw and fresh. Heat flattens the flavour, so cooks stir it in at the end.

Wash bunches well under running water before use. Raw herbs have been linked to food-borne illness when grown or rinsed in unclean water.

Store stems in a glass of water in the fridge, covered loosely.

What are the side effects of cilantro?

• Allergic reaction: itching, hives, swelling of the lips or face
• Itchy mouth or throat in people allergic to celery, carrot, fennel, caraway or dill
• Rare severe allergy with trouble breathing
• Skin rash from handling crushed leaves or the oil
• Sun sensitivity on skin that touched the sap or oil
• Loose stools or stomach upset after very large amounts
• A soapy taste, which is a genetic quirk and harmless

Good to know:

Side effects are uncommon at food amounts. Most people eat cilantro all their lives with no trouble.

Allergy is the one real risk, and it is more likely if you react to other plants in the carrot family. Severe reactions are rare but can be dangerous.

The essential oil is a different matter. It is concentrated and can burn skin or irritate the gut.

How much cilantro should you take?

• Recommended daily: Cilantro is a food, so most people use handfuls, not doses. A garnish is a small handful of fresh leaves, roughly a few grams. Whole bunches go into salsas and soups with no concern. Capsule labels usually carry 400 mg to 600 mg of leaf extract, taken once or twice a day. That is what labels print. It is not a plan for you, and it is not backed by trials. Food amounts have by far the longest record of safe use.
• Best time of day: Timing does not matter for the fresh herb. Eat it whenever it suits the meal. Folk use put the calming tea in the evening. That is custom, not evidence.
• With or without food: Cilantro is normally eaten with food, and that suits most stomachs. If you take capsules, taking them with a meal lowers the chance of queasiness. Large amounts of leaf juice on an empty stomach may feel harsh.
• Time to effect: For settling after a meal, people say they notice something within an hour or not at all. For blood sugar or blood fats, no reliable timeline exists, because the leaf has not been shown to change them in people. Be ready for it to do nothing. That is a fair expectation for a food herb used as a remedy.
• How long to take it: As a food herb, cilantro can be part of your diet for life. That is how it has been used for centuries. For capsules, extracts and detox blends, no one can give an honest length of use. Studies long enough to answer that have not been done. People who try them usually use them for a few weeks. If you have taken a supplement for weeks with no change, stopping is reasonable.