Overview

Water hemlock is considered to be the most poisonous plant growing in North America. All parts of the water hemlock are toxic and can cause death in as little as 15 minutes.

Water hemlock grows in marshy, swampy areas of meadows; and along banks of streams, pools, and rivers. Accidental poisonings usually occur when water hemlock is mistaken for edible plants such as artichokes, celery, sweet potatoes, sweet anise, or wild parsnip.

Even though water hemlock is extremely poisonous, it is used as a medicine for migraine headaches, painful menstruation, and worms in the intestines.

Some people apply water hemlock directly to the skin for redness and swelling (inflammation).

How does it work ?

Water hemlock contains ingredients that are poisonous and have many dangerous effects on the body.

Water hemlock contains ingredients that are poisonous and have many dangerous effects on the body.

Uses & Effectiveness ?

Insufficient Evidence for

  • Migraine headaches.
  • Painful menstrual periods.
  • Intestinal worms.
  • Skin redness and swelling (inflammation), when applied to the affected area.
  • Other conditions.
More evidence is needed to rate the effectiveness of water hemlock for these uses.

Side Effects

Water hemlock is UNSAFE for anyone to take by mouth or apply to the skin. All plant parts are poisonous and can cause death in as little as 15 minutes. Even applying water hemlock to your skin can cause death. Get immediate medical attention if you have taken water hemlock. The first symptoms of water hemlock poisoning are drooling, nausea, vomiting, wheezing, sweating, dizziness, stomach pain, flushing, weakness/tiredness (lethargy), delirium, and uncontrollable bowel movements. These are followed by more serious symptoms including trouble breathing, convulsions, heart problems, kidney failure, coma, and death.

Special Precautions and Warnings

Water hemlock is UNSAFE for anyone to take by mouth or apply to the skin. All plant parts are poisonous and can cause death in as little as 15 minutes. Even applying water hemlock to your skin can cause death. Get immediate medical attention if you have taken water hemlock. The first symptoms of water hemlock poisoning are drooling, nausea, vomiting, wheezing, sweating, dizziness, stomach pain, flushing, weakness/tiredness (lethargy), delirium, and uncontrollable bowel movements. These are followed by more serious symptoms including trouble breathing, convulsions, heart problems, kidney failure, coma, and death. It is UNSAFE for anyone to use water hemlock, but some people have extra reasons to avoid use.

Children: Use of water hemlock is UNSAFE and can be fatal, especially in children. Children can be poisoned by even small amounts of water hemlock. Some children have died after just using hollow water hemlock stems as peashooters, flutes, or whistles; or rubbing the plant on their skin.


Pregnancy and breast-feeding: Use of water hemlock is UNSAFE and can be fatal for both the mother and her unborn child.

Interactions ?

    Moderate Interaction

    Be cautious with this combination

  • Lithium interacts with WATER HEMLOCK

    Water hemlock might have an effect like a water pill or "diuretic." Taking water hemlock might decrease how well the body gets rid of lithium. This could increase how much lithium is in the body and result in serious side effects. Talk with your healthcare provider before using this product if you are taking lithium. Your lithium dose might need to be changed.

Dosing

The appropriate dose of water 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 water 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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CONDITIONS OF USE AND IMPORTANT INFORMATION: This information is meant to supplement, not replace advice from your doctor or healthcare provider and is not meant to cover all possible uses, precautions, interactions or adverse effects. This information may not fit your specific health circumstances. Never delay or disregard seeking professional medical advice from your doctor or other qualified health care provider because of something you have read on WebMD. You should always speak with your doctor or health care professional before you start, stop, or change any prescribed part of your health care plan or treatment and to determine what course of therapy is right for you.

This copyrighted material is provided by Natural Medicines Comprehensive Database Consumer Version. Information from this source is evidence-based and objective, and without commercial influence. For professional medical information on natural medicines, see Natural Medicines Comprehensive Database Professional Version.
© Therapeutic Research Faculty 2020.