Other Name(s):

California Fern, Carrot Weed, Cicuta, Ciguë, Ciguë d'Athènes, Ciguë Officinale, Ciguë de Socrate, Ciguë Tachetée, Conium, Conium Maculata, Conium maculatum, Grande Ciguë, Mort aux Oies, Nebraska Fern, Poison Fool's Parsley, Poison-Hemlock, Spotted Hemlock, Tsuga, Vicaire, Wild Carrot.


Hemlock is a very poisonous plant. In fact, all parts of the plant are toxic. Hemlock is most poisonous during the early stages of growth in the spring, but it is dangerous at all stages of growth. The poisons in hemlock are so deadly that people have died after eating game birds that had eaten hemlock seeds.

Hemlock is native to Europe and western Asia and was introduced into North America as an ornamental plant. It is frequently found in the US and southern Canada. Hemlock typically grows near fences, roadsides, ditches, abandoned construction sites, pastures, crops, and fields, where it can be confused with harmless plants. Accidental poisonings have occurred when people mistook the root for parsnip, leaves for parsley, or seeds for anise.

Despite serious safety concerns, hemlock leaves, root, and seeds are used to make medicine. It is used for breathing problems including bronchitis, whooping cough, and asthma; and for painful conditions including teething in children, swollen and painful joints, and cramps.

Hemlock is also used for anxiety and mania. Other uses include treatment of spasms tumors, skin infections, epilepsy, Parkinson's disease, Sydenham's chorea, and bladder infections.

Hemlock has also been used to reverse strychnine poisoning.

How does it work?

Hemlock contains poisons that affect the transmission of nerve impulses to muscle. Death occurs by respiratory failure.

Uses & Effectiveness

Insufficient Evidence to Rate Effectiveness for...

More evidence is needed to rate the effectiveness of hemlock for these uses.

Natural Medicines Comprehensive Database rates effectiveness based on scientific evidence according to the following scale: Effective, Likely Effective, Possibly Effective, Possibly Ineffective, Likely Ineffective, and Insufficient Evidence to Rate (detailed description of each of the ratings).


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Side Effects

All parts of hemlock, including seeds, flowers, and fruits, are UNSAFE. Hemlock is so poisonous it can cause death. If someone takes hemlock, he or she should get immediate medical attention. Side effects and toxicities include increased saliva, burning of the digestive tract, drowsiness, muscle pain, rapid swelling and stiffening of muscles, kidney damage, rapid breakdown of muscle tissue and release of muscle tissue byproducts into the blood, rapid heart rate followed by a decreased heart rate, loss of speech, paralysis, unconsciousness, heart, lung, and kidney failure, and death.

Special Precautions & Warnings

It is UNSAFE for anyone to use hemlock, but people with the following conditions are especially likely to experience unwanted side effects.

Children: Use of hemlock is UNSAFE and can be fatal, especially in children. Children can be poisoned by even small amounts of hemlock. Some children have died after eating leaves or using hollow hemlock stems as peashooters, flutes, or whistles. Hemlock should not be used for treating pain in children due to teething.

Pregnancy and breast-feeding: Use of hemlock is UNSAFE and can be fatal.


The appropriate dose of hemlock depends on several factors such as the user's age, health, and several other conditions. At this time there is not enough scientific information to determine an appropriate range of doses for hemlock. Keep in mind that natural products are not always necessarily safe and dosages can be important. Be sure to follow relevant directions on product labels and consult your pharmacist or physician or other healthcare professional before using.


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Reviewed on 6/14/2021

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