Hemlock Water Dropwort Drug Interactions, Uses, Safety & More

Hemlock water dropwort (Oenanthe crocata) is a wild flowering plant in the carrot and parsley family (Apiaceae). It grows in wet places such as ditches, riverbanks, marshes, and damp meadows, mainly in Britain, Ireland, and parts of western Europe.

The plant has clusters of small white flowers and finely divided leaves, and its thick roots are sometimes mistaken for edible plants like wild parsnip or water parsley. This mistake has caused many serious and even fatal poisonings.

Unlike most herbs covered on this site, hemlock water dropwort is not sold or used as a dietary supplement. It is included here mainly as a safety warning because it is one of the deadliest plants in Europe.

There is no proven or accepted medicinal use for hemlock water dropwort. In the past, some people applied it to the skin in folk remedies, but this practice is dangerous and is not supported by evidence.

Most modern scientific interest in the plant comes from toxicology — the study of poisons — rather than from any health benefit. Researchers have studied it to understand how its toxins affect the body and to learn how to treat poisoned patients.

In short, there is no condition for which this plant should be used. Any claimed benefit is far outweighed by the very real risk of death.

The plant contains powerful natural toxins, most notably oenanthotoxin. This compound interferes with the chemical messengers in the nervous system, especially a signal called GABA that normally helps calm nerve activity.

When that calming signal is blocked, the nervous system becomes overactive. This can trigger violent seizures and disrupt the normal rhythm of the heart. The roots tend to hold the highest concentration of toxin, which is why root poisonings are especially dangerous.

These effects are well documented in human poisoning cases and in laboratory research. This is not a theoretical risk — it is a confirmed, serious poison.

Hemlock water dropwort should never be eaten, brewed into tea, juiced, or taken in any form. Poisonings often happen when foragers confuse the roots with edible plants.

If you spend time near streams, ditches, or wetlands, learn to recognize this plant and keep children and pets away from it. Touching the plant and then your mouth, or handling cut roots, can be risky.

It is unsafe during pregnancy and breastfeeding, just as it is unsafe for everyone else. If you suspect someone has eaten any part of this plant, treat it as a medical emergency and call your local poison control center or emergency services immediately.

Poisoning can come on quickly and may include nausea, vomiting, excess saliva, sweating, and stomach pain. These early signs can rapidly progress to far more serious effects.

Severe poisoning can cause violent seizures, loss of consciousness, irregular heartbeat, breathing failure, and death. People affected by this plant have sometimes been found with a fixed grimace, a feature historically linked to its poisoning.

Because the toxin is so potent, there is no safe amount. Any exposure should be taken seriously.

There is no safe dose of hemlock water dropwort. It is a poison, not a supplement, and should never be measured out or taken for any reason.

If you have been given a product that claims to contain this plant, do not use it, and speak with a pharmacist or doctor. The only correct "dose" is none at all.