Urtica dioica, commonly known as stinging nettle, is an edible, perennial plant with spiny leaves that grows in many areas of the world, including North America, Europe and Asia.
It can be consumed as a vegetable and is also used in supplement form as a natural remedy for conditions like arthritis and diabetes.
Here’s everything you need to know about stinging nettle, including its potential health benefits, possible side effects, and safety.
Dietary supplements are minimally regulated by the FDA and may or may not be suitable for you. The effects of supplements vary from person to person and depend on many variables, including type, dosage, frequency of use, and interactions with current medications. Please speak with your healthcare provider or pharmacist before starting any supplements.
Stinging nettle has been used as a natural medicine for over 2,000 years. The plant's leaves and roots contain therapeutic compounds, such as polyphenols like kaempferol and quercetin, and carotenoids like beta-carotene and lutein, all of which have anti-inflammatory and antioxidant properties.
When taken as a supplement, stinging nettle may be helpful for certain conditions. However, human research on its potential health benefits is currently limited. Plus, many studies investigating the effects of stinging nettle on human health have used products containing a combination of ingredients, not just stinging nettle.
It May be Helpful for Arthritis Symptoms
Stinging nettle has been used for hundreds of years as a natural treatment for inflammatory conditions like arthritis. Some evidence suggests that stinging nettle may help reduce certain symptoms of osteoarthritis, an inflammatory disease that affects joints like the knees, hips, and wrists.
A 2009 study that included 81 people with osteoarthritis of the knee or hip found that treatment with a supplement called Phytalgic®, which contains fish oil, stinging nettle, zinc, and vitamin E, for three months significantly reduced the use of pain medication and significantly reduced symptoms like stiffness and pain compared to a placebo treatment.
Even though these results are promising, the study was funded by Laboratoires Phythea, which is the company that manufactures Phytalgic®, which could have influenced the study results.
Older research suggests that topical treatment with stinging nettle may be helpful for arthritis-related pain of the fingers and cell studies suggest that extracts of stinging nettle leaves, roots, and stems contain powerful compounds that may be used to treat inflammatory disorders in the future.
It May Help Reduce BPH Symptoms
Benign prostatic hyperplasia (BPH) is a medical condition that causes a non-cancerous enlargement of the prostate. Commonly referred to as enlarged prostate, BPH is common amongst men over the age of 60.
BPH causes urinary symptoms like urinary retention, a weak urine stream, and incomplete emptying of the bladder.
A few studies have found that stinging nettle may benefit people who have BPH by helping reduce BPH-associated symptoms.
A 2013 study in 100 men with BPH found that the men treated with 1,200 mg of stinging nettle for eight weeks reported a greater improvement in BPH symptoms compared to the men treated with a placebo.
A more recent 2020 study in 60 men with BPH found that treatment with 450 mg of stinging nettle root extract per day for twelve weeks significantly improved BPH symptoms compared to a placebo. The researchers also found that the stinging nettle treatment reduced inflammatory markers like C-reactive protein (CRP) and malondialdehyde (MDA).
Older studies have also shown similar results.
Although these results are promising, more research is needed to fully understand the effects of stinging nettle supplements on BPH symptoms.
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It May Benefit People with Type 2 Diabetes
Certain phenolic compounds concentrated in stinging nettle may have the ability to inhibit enzymes involved in carbohydrate digestion, which may benefit people with diabetes.
A 2020 review of eight studies that included 401 people found that stinging nettle supplements were effective for reducing fasting blood sugar levels in people with type 2 diabetes.
A 2016 study in 50 women with type 2 diabetes found that participants who supplemented with stinging nettle extract three times per day after meals for eight weeks experienced significant reductions in fasting blood sugar, triglyceride levels, and liver enzyme levels compared to a placebo treatment. The participants also experienced significant increases in protective HDL cholesterol and the antioxidant enzyme superoxide dismutase (SOD), which helps protect cells against oxidative damage.
How to Use Stinging Nettle
Stinging nettle is most commonly taken in capsule form, but it can also be taken as a liquid or consumed as a tea.
Supplements often combine stinging nettle with other herbs and ingredients such as saw palmetto and quercetin, so it’s important to read supplement labels before purchasing stinging nettle products.
Studies investigating the effects of stinging nettle in humans often used divided doses of stinging nettle given at different times of day, such as after meals. Most supplement labels instruct users to take stinging nettle multiple times per day, between meals.
Keep in mind that supplements can contain extracts from different parts of the stinging nettle plant, such as leaf or root extracts.The leaves, roots, and stems all contain medicinal compounds, but it's unclear how different parts of the stinging nettle plant impact health.
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Dosage recommendations vary depending on which type of stinging nettle supplement you use. Most studies and products on the market recommend taking between 450 to 1,200 mg per day.
Is Stinging Nettle Safe?
Stinging nettle supplements aren’t safe for everyone, so it’s important to check with your doctor before using any stinging nettle product.
Oral and topical stinging nettle products may lead to side effects, some of which may harm your health. For example, stinging nettle may cause blood sugar to decrease, which could be dangerous for people who have trouble regulating their blood sugar levels.
Nettle tea intake has also been linked to cases of gynaecomastia in a man and hyperestrogenism in a woman. Gynaecomastia is a condition that causes enlarged breast tissue in men. Hyperestrogenism is a term used to describe high estrogen levels in the body.
Stinging nettle shouldn't be used by people who are pregnant or breastfeeding as it can act as a diuretic, which increases the excretion of salt and water from your body. This can lead to dehydration and other side effects that can be especially harmful during pregnancy and breastfeeding.
Potential Drug Interactions
Stinging nettle has the potential to interact with several medications, including:
- CYP450 substrates: Stinging nettle may interact with drugs that are metabolized by cytochrome P450 enzymes, including the blood thinner Warfarin and the blood pressure medication metoprolol.
- Diuretics: Because stinging nettle may act as a diuretic in the body, it could increase the effect of diuretic medications, like furosemide and spironolactone.
- Blood pressure-lowering medications: Stinging nettle may enhance the action of blood pressure-lowering medications, which could lead to dangerously low blood pressure levels.
In addition to the medications listed above, stinging nettle may interact with other commonly prescribed drugs. If you’re taking one or more medications, check with your doctor to make sure it’s safe for you to supplement with stinging nettle.
What to Look For
When shopping for dietary supplements, it’s important to purchase supplements from brands who adhere to strict safety and quality standards.
Choosing supplements from brands certified by third party organizations like United States Pharmacopeia (USP)—a nonprofit organization that sets standards for the purity and quality of dietary supplements—is recommended by experts in the nutrition field as a way to ensure supplement safety.
Stinging nettle can be found and foraged near streams, along trails, and old farm sites. However, you shouldn’t forage for stinging nettle unless you’re experienced. Touching the plant can cause skin irritation and symptoms like pain, burning, and itching, which can last for several hours.
Can You Take Too Much Stinging Nettle?
When taken in recommended doses, stinging nettle is considered safe. However, it may be possible to take too much.
Stick to the recommended doses on supplement labels and always check with your healthcare provider before taking stinging nettle.
Stinging nettle supplements aren’t linked with many adverse effects. However, in some cases, stinging nettle may cause the following side effects:
- Low blood sugar levels
- Diarrhea
- Skin irritation if used topically
Touching stinging nettle plants can also cause skin irritation, including pain, burning, and itching.
A Quick Review
Stinging nettle is a plant that’s been used as a natural remedy for thousands of years.
Some research suggests taking stinging nettle supplements could be helpful for certain health conditions, like arthritis, BPH, and diabetes. However, human research is limited at this time.
Stinging nettle supplements may interact with commonly prescribed medications and may influence blood sugar levels, so it’s not safe for everyone.
If you’re interested in trying stinging nettle supplements, it’s important to run it by your healthcare provider first, especially if you’re currently taking one or more medications.
