Stinging Nettle
OTHER NAME(S): stinging nettle, Urtica dioica
Overview
Stinging nettle is a plant called Urtica dioica. Dietary supplements that contain stinging nettle are usually made from the roots of the plant. Stinging nettle is commonly used for an enlarged prostate, although its benefits are not well defined. Common side effects include constipation, diarrhea, or upset stomach. Before taking stinging nettle, make sure to tell your health care provider about any health conditions you have or medicines you are taking.
Uses
What is stinging nettle used for?
Stinging nettle (Urtica dioica) is commonly taken for an enlarged prostate (benign prostatic hyperplasia, or BPH), but its benefits for any use are not well defined.
Note: The FDA has not reviewed stinging nettle for safety and effectiveness. Learn more about dietary supplements here.
How does stinging nettle work (mechanism of action)?
Stinging nettle is a plant called Urtica dioica. Dietary supplements that contain stinging nettle are usually made from the roots of the plant. However, other parts of the plant, including the leaves and flowers, may also be found in some supplements and teas.
Stinging nettle is commonly marketed for the treatment of an enlarged prostate. When the prostate is enlarged, it can become difficult to fully empty your bladder. This may increase how often you need to pee throughout the day and night.
Some studies show that stinging nettle might help reduce some symptoms of benign prostatic hyperplasia (BPH). But these benefits seem to be small, and it is not clear if they would be meaningful to most people. It is also not clear how stinging nettle compares with prescription medicines for BPH.
Herbal products, like stinging nettle, naturally contain many different chemicals. The amounts of each chemical in a specific stinging nettle product may vary. Some, none, or all of these chemicals may have effects on the body. These effects may change depending on how much of each chemical is found in the product you are using.
How should I store stinging nettle?
You should store stinging nettle according to the product label. Most dietary supplements should be kept in a cool, dry location that is out of the reach of children and pets and not in direct sunlight.
Side Effects
What are the most common side effects of stinging nettle?
The most common side effects of stinging nettle are listed below. These side effects may vary depending on the dose you are taking or the specific product you are using. Tell your health care provider if you have any of these side effects that bother you.
- Constipation or diarrhea
- Upset stomach
There may be other side effects of stinging nettle that are not listed here. Contact your health care provider if you think you are having a side effect of a supplement. In the U.S., you can report side effects to the FDA at www.safetyreporting.hhs.gov or by calling 888-SAFEFOOD (888-723-3366). In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.
What are the serious side effects of stinging nettle?
While less common, the most serious side effects of stinging nettle are described below, along with what to do if they happen.
Severe Allergic Reactions. Stinging nettle may cause allergic reactions, which can be serious. Stop taking stinging nettle and get help right away if you have any of the following symptoms of a serious allergic reaction.
- Breathing problems or wheezing
- Racing heart
- Fever or general ill feeling
- Swollen lymph nodes
- Swelling of the face, lips, mouth, tongue, or throat
- Trouble swallowing or throat tightness
- Itching or skin rash
- Bumps on the skin called hives that can be red, pink, white, or brown depending on your skin tone
- Nausea or vomiting
- Dizziness, feeling lightheaded, or fainting
- Stomach cramps
- Joint pain
Skin Irritation or Stinging.Fresh stinging nettle leaves contain sharp hairs that are covered with irritants. These leaves can cause stinging and irritation when they come into contact with your skin. Do not touch fresh stinging nettle with your bare skin or place it in your mouth. Cooking the leaves or processing them into powder will remove the hairs. The other parts of the stinging nettle plant, such as the flowers and roots, do not cause stinging or irritation.
Precautions
Who should not use stinging nettle?
Allergies to Ingredients. People who are allergic to any of the following should not take stinging nettle.
- Stinging nettle
- Urtica dioica
- Any of the ingredients in the specific product
Your pharmacist can tell you all of the ingredients in the specific stinging nettle products they stock.
What should I know about stinging nettle before using it?
Stinging nettle is a dietary supplement. It cannot be marketed to treat or cure a disease.
Read and follow the directions on the specific product you are using, or use it as recommended by your health care provider.
Keep stinging nettle out of the reach of children.
If you have symptoms of an enlarged prostate, such as having a hard time peeing, a weak stream, or dribbling when you pee, call your health care provider. Stinging nettle may not be an appropriate option for treating prostate problems or other urinary problems.
Herbal products, such as stinging nettle, naturally contain many different chemicals. The amount of each chemical in a specific stinging nettle product can change for many reasons, including the area where the plant was grown, the weather during growth, the time of year when it was harvested, and the way the plant was processed after being harvested. If you switch to a new bottle or a different brand, you may not have the same effects or side effects because of this variability. Talk to your health care provider if you have questions or concerns.
Stinging nettle is available in many forms, including as a liquid extract, tea, capsule, or dried ground powder. Each of these forms may contain different amounts of the chemicals naturally found in the plant.
Stinging nettle may be made from different parts of the plant, including the roots, leaves, and flowers. Each of these plant parts contains different chemicals that may have different effects in the body. Most of the research on stinging nettle has used the roots of the plant. It is important to read the label to confirm which part of the plant was used to make that product.
The FDA has not tested stinging nettle products to confirm that they contain the ingredients stated on their labels. Some dietary supplements have been tested by third-party organizations to confirm that they contain the ingredients listed on their labels and do not contain any harmful chemicals. Learn more about how to choose a safe dietary supplement product here.
What should I tell my health care provider before using stinging nettle?
Tell your health care provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them know if stinging nettle is right for you.
In particular, make sure that you discuss any of the following.
Current and Past Health Conditions.Tell your health care provider if you have any of the following.
- Kidney problems
- Liver problems
Other Medicines and Supplements.Stinging nettle may interact with other medicines and supplements. Before taking stinging nettle, tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.
Pregnancy. Stinging nettle is not usually used by people who can become pregnant. It is not known if or how stinging nettle could affect pregnancy or harm a fetus. Tell your health care provider if you are pregnant or plan to become pregnant.
Breastfeeding. Stinging nettle is not usually used by people who can breastfeed. It is not known if stinging nettle passes into breast milk. Tell your health care provider if you are breastfeeding or plan to breastfeed.
Interactions
Does stinging nettle interact with foods or drinks?
There are no known interactions between stinging nettle and foods or drinks.
It is unknown if drinking alcohol will affect stinging nettle.
Does stinging nettle interact with medicines (drug interactions)?
Always tell your health care provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.
In particular, make sure that you discuss if you are using any of the following before taking stinging nettle.
- A diuretic, also called a water pill, which is a medicine used to reduce edema (fluid retention) and blood pressure
- An alpha-blocker, such as alfuzosin, doxazosin, prazosin, or tamsulosin, which is a medicine that may be used for trouble peeing due to an enlarged prostate
- Any other supplements for prostate health
The interactions between stinging nettle and medicines are not fully understood. As with most dietary supplements, the research on drug interactions with stinging nettle is incomplete. Always check with your health care provider before taking stinging nettle with any medicines.
Dosing
What should I do if I accidentally use too much stinging nettle?
If you or someone else has used too much stinging nettle, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.
Read the product label closely and speak to a health care provider about how to take stinging nettle safely. Do not take double or extra doses, even if you miss a dose.
References
- European Medicines Agency: “Assessment report on Urtica dioica L.; Urtica urens L., radix,” “European Union herbal monograph on Urtica dioica L., Urtica urens L., radix.”
- Gardner, Z; McGuffin, M. Botanical Safety Handbook (Second Edition), American Herbal Products Association, 2013.
- National Library of Medicine: LiverTox: Clinical and Research Information on Drug-Induced Liver Injury [Internet]: “Stinging Nettle.”
- National Cancer Institute NCI Drug Dictionary: “Urtica dioica extract.”
- National Center for Complementary and Integrative Health: “Benign Prostatic Hyperplasia and Complementary and Integrative Approaches: What the Science Says.”