As far back as medieval times, stinging nettle root has been used medicinally. These days, Urtica dioica is considered an alternative supplement, but nettle root benefits include helping with conditions such as allergies, high blood pressure and benign prostatic hyperplasia.
Stinging nettles are probably best known for the itchy, painful rash they leave on your skin when you come into contact with their leaves and stems. This is thanks to the nettle's tiny hairs that contain irritating chemicals, according to the Penn State Milton S. Hershey Medical Center (PennState Hershey). However, the root is also available in multiple forms, including extracts, tinctures, capsules, tablets, juices and teas, which can be taken as a supplement.
Nettle's Antioxidant Content
Incorporating antioxidants into your diet can help you to fight off the free radicals that damage your cells and play a role in conditions such as heart disease and cancer. Antioxidants are molecules that protect your body against free radicals, according to the Mayo Clinic. Free radicals come from both everyday activities such as your body breaking down food and harmful lifestyle activities such as smoking cigarettes.
A small study published in the November-December 2016 issue of the Avicenna Journal of Phytomedicine that looked at the effect of Urtica dioica as an antioxidant on Type 2 diabetes found that stinging nettles contain antioxidants. The study concluded that taking a stinging nettle extract could decrease the risk of heart disease and other complications for people with diabetes mellitus.
Another study, published in September 2016 in the French journal Comptes Rendus Chimie, considered the effect of the antioxidants in stinging nettle extract for cosmetic applications. The researchers concluded that the antioxidants in nettle extract have anti-aging potential by inhibiting certain enzyme activity such as elastase and collagenase.
Read more: OK, But What Are Antioxidants Really?
Treating Benign Prostatic Hyperplasia
As men age, they can develop benign prostatic hyperplasia (BPH), also known as prostate gland enlargement. According to the Mayo Clinic, this common condition causes problematic symptoms, such as difficulty urinating or a frequent or urgent need to urinate, and can lead to bladder, urinary tract or kidney problems.
It isn't clear what causes the prostate to enlarge nor is the size of the prostate indicative of the severity of a man's symptoms. Family history and lifestyle habits, such as exercise, might play a role in developing the condition.
Stinging nettle root extract could help treat those symptoms, according to a review of studies published in February 2016 in the African Journal of Traditional, Complementary and Alternative Medicines.
Researchers looked at four double-blind, controlled studies that involved more than 1,100 participants and concluded that stinging nettle root is a safe and effective treatment for low urinary tract symptoms associated with BPH. According to PennState Hershey, stinging nettle root is a common treatment for BPH in Europe.
Beating Hay Fever Symptoms
More than 40 million Americans suffer from allergic rhinitis, colloquially known as hay fever, according to the American College of Allergy, Asthma & Immunology. Despite its nickname, the allergies aren't just triggered by hay; both outdoor and indoor allergens, including grass, trees, pet hair and mold, can lead to a runny nose, itchy eyes, sneezing and a stuffy nose. Hay fever can also be associated with irritability, sleeping problems, fatigue and impaired concentration and focus.
Stinging nettle root extract may improve the symptoms of allergic rhinitis, notes a small study published in winter 2017 in the Iranian Journal of Pharmaceutical Research. However, there wasn't enough of a difference in participants taking nettle root extract versus those taking a placebo for researchers to definitively declare its effectiveness, so additional larger studies are needed.
Before taking stinging nettle supplementation for hay fever, talk to an allergist about whether it's a good idea for you.
Improving Blood Pressure
Stinging nettle may help improve a person's blood pressure, especially in those who suffer from hypertension. A September 2016 animal study from the Journal of Translational Medicine indicated that stinging nettle extract possesses an antihypertensive effect, though human studies are needed. The supplement may work by acting as a calcium channel blocker, which reduces the force of contractions and relaxes your heart.
A second animal study, published in Phytomedicine in July 2018, also found that supplementation with stinging nettle extract has beneficial effects on hypertension. The study determined the positive effect of stinging nettle's antioxidant power on oxidative stress in rats.
However, because stinging nettle can lower blood pressure, it could make the effects of medications for high blood pressure stronger, according to Beaufort Memorial Hospital. Drugs that could potentially be affected include ACE inhibitors such as elaropril and captopril, beta blockers such as atenolol and propranolol, and calcium channel blockers such as nifedipine and verapamil.
Read more: The 10 Best Supplements
Giving Relief From Arthritis
Arthritis isn't just one condition, but rather a way of referring to joint pain or joint disease. According to the Arthritis Foundation, arthritis is extremely common — there are more than 100 different types of arthritis that affect some 50 million adults and 300,000 children in the United States. Common symptoms, however, include swelling, stiffness, pain and decreased range of motion in the affected joints, which can result in chronic pain and difficulty in daily activities such as walking.
Stinging nettle root extract might help relieve the symptoms of arthritis, concluded a study published in Phytomedicine in January 2014. The researchers looked at how the extract of stinging nettle root, along with the extract from the stems, leaves and flowers, affected inflammation, finding that the extracts of the root, stems and leaves exhibit potent anti-inflammatory effects.
They noted that these extracts may be more effective than traditional treatments, such as tinctures, for inflammatory disorders such as arthritis.
Taking Stinging Nettle Root
Even though stinging nettle root has been taken for hundreds of years, it's not right for everyone — particularly people who might be taking other medications or supplements. Talk to your health care provider about nettle root benefits and whether it's a safe option for you.
According to PennState Hershey, stinging nettle root can cause mild side effects, including an upset stomach, diarrhea, fluid retention or sweating. If you use it topically, you might experience a hive or rash. Additionally, stinging nettle can affect a woman's menstrual cycle and could be linked to miscarriage, PennState Hershey states, so pregnant women should avoid it entirely.
Although there's evidence that stinging nettle root can help with blood sugar levels, it might also interfere with diabetes management, so patients should talk to their doctors before supplementing.
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- PennState Hershey: Milton S. Hershey Medical Center: "Stinging Nettle"
- Iranian Journal of Pharmaceutical Research: "Efficacy of Supportive Therapy of Allergic Rhinitis by Stinging Nettle (Urtica dioica) Root Extract: A Randomized, Double-Blind, Placebo-Controlled, Clinical Trial"
- Journal of Translational Medicine: "Mechanisms Underlying the Antihypertensive Properties of Urtica dioica"
- Phytomedicine: "Urtica dioica L. Leaf Extract Modulates Blood Pressure and Oxidative Stress in Spontaneously Hypertensive Rats"
- Avicenna Journal of Phytomedicine: "Effects of Urtica dioica Supplementation on Blood Lipids, Hepatic Enzymes and Nitric Oxide Levels in Type 2 Diabetic Patients: A Double Blind, Randomized Clinical Trial"
- Mayo Clinic: "Antioxidants: Why Are They Important?"
- Comptes Rendus Chimie: "Nettle (Urtica dioica L.) as a Source of Antioxidant and Anti-Aging Phytochemicals for Cosmetic Applications"
- American College of Allergy, Asthma & Immunology: "Allergic Rhinitis"
- Mayo Clinic: "Benign Prostatic Hyperplasia (BPH)"
- Beaufort Memorial Hospital: "Possible Interactions With: Stinging Nettle"
- Arthritis Foundation: "What Is Arthritis?"
- Phytomedicine: "Lipophilic Stinging Nettle Extracts Possess Potent Anti-Inflammatory Activity, Are Not Cytotoxic and May Be Superior to Traditional Tinctures for Treating Inflammatory Disorders"
- African Journal of Traditional, Complementary and Alternative Medicines: "The Efficacy and Safety of Urtica dioica in Treating Benign Prostatic Hyperplasia: A Systematic Review and Meta-Analysis"