Nettle Tea Benefits and Warnings

Have you ever been stung by a nettle? It's hard to forget that burning sensation, the pain and burning from hives and blisters. Stinging nettles are found all over the world, and bloom every year. It's almost impossible to get away from the invasive plant.

In one of those strange-but-true twists of nature, it turns out that the plant causing you so much harm could be the very solution to treating your problems.

The stinging nettle, Latin name, Urtica dioica, has been used medicinally since at least 3 B.C. In medieval times, it was used to treat pain in joints, as well as act as a diuretic. Today, nettle root is used to treat a variety of ailments (keep reading for more!).

The leaves and stems can be eaten in a salad, cooked into soup or made into a tea, but the nettle root is more likely to be extracted with alcohol to make a tincture, dried and taken in capsules, or dried and made into a tea. Nettle tea side effects are rare, notes the University of Michigan, but as with any medicinal preparation, you may want to consult a health care practitioner before adding nettles to your diet or treatment plan.

Nettle tea affects the kidneys directly. "Nettle is a diuretic. [It] increases urine output and removal of uric acid (under physician supervision). Thus it can be useful for edema, inflammatory arthritis or gout," says naturopathic doctor Robert Kachko.

Nettle is often used for urinary issues, such as frequency, irritable bladder, and infections. In addition to affecting the kidneys, "nettle has many constituents and is considered one of our most nutritive herbs, we call it a 'trophorestorative' for this reason," says Dr. Kachko. "Its main constituents are flavonoids (quercetin, kaempferol), carotenoids, Vitamin C, Vitamin B, Vitamin K, triterpenes, sterols and minerals."

Read more: 10 Everyday Ailments Soothed by Tea

Hay fever and seasonal allergies, clinically referred to as allergic rhinitis, affects millions of people, and nettle tea is effective in controlling the itching and sneezing typically associated with it.

A study at the National College of Naturopathic Medicine concluded that 58 percent of the participants who were given freeze-dried nettle for treatment of allergic rhinitis, or hay fever, experienced a reduction in symptoms and 48 percent concluded it was more effective than over the counter medications. Since over-the-counter and prescription antihistamines can have side effects like drowsiness, seizures and dry mouth, nettle tea may be a good alternative for people with sensitivities.

Read more: LIVESTRONG.COM's Seasonal Allergies Condition Center

The diuretic nature of nettle tea improves kidney function, and as a result can improve the symptoms associated with BPH. It "improves frequency, urgency, urinary flow, and can also lower the sex hormone binding globulin which impacts testosterone levels," says naturopathic doctor Robert Kachko.

The National Institutes of Health indicate that studies have shown effectiveness in nettle in improving the lower urinary tract symptoms usually associated with BPH, when combined with saw palmetto (Serenoa repens).

Despite anecdotal evidence, there's really no medical research to prove that nettle tea promotes hair growth or eliminates acne. However, herbalists do use it for hair growth, claiming the silica in nettles strengthens hair and nails and other properties improve circulation and reduces shedding.

When included in a topical ointment or even ingested as a tea, nettle may have anti-inflammatory and analgesic effects for skin problems like eczema or rashes. On the contrary, however, there are reports of allergic skin reactions to topical nettle, so buyer beware. The book Integrative Medicine says that stinging nettle is useful in the treatment of hives or urticaria. While the hairs of the nettle leaf contain histamine and often cause hives, the extract of the leaves may contain compounds which can soothe hives because it turns off the inflammatory response.

In some studies conducted on animals, stinging nettle has been shown to lower blood pressure levels. However, this effect has not yet been shown in human studies. The ability for the herb to lower blood pressure likely occurs because it works as a diuretic in the body, which in turn may lower blood pressure, Memorial Sloan-Kettering Cancer Center reports.

Because high blood pressure is a serious medical condition, you should not use nettle to treat it unless you have first consulted with a knowledgeable medical professional.

There has been some preliminary research regarding the use of nettle tea for treating type 2 diabetes, and a 2011 study, published in the Pakistan Journal of Biological Sciences did find that it was effective in decreasing interleukin 6 (IL-6) and high sensitive c-reactive protein (hs-CRP), markers of inflammation, in diabetic patients versus a control group after eight weeks of treatment.

A 2013 study published in Clinical Laboratory discovered that nettles had a significant effect on the glucose levels of people with type 2 diabetes. However, patients should note that researchers studied "taking nettle leaf extract (one 500 mg capsule every 8 hours for 3 months) combined with the conventional oral anti-hyperglycemic drugs", so nettle tea could be a good complementary treatment, especially for pre-diabetics.

Read more: LIVESTRONG.COM's Diabetes Condition Center

A 2013 issue of Phytomedicine found that stinging nettle, including the root, when extracted into an oil-based solution, helped reduce inflammation. Great potential for treating arthritis was indicated, but further study is still required.

The anti-inflammatory properties of stinging nettles may in fact help those suffering from arthritis. Moreover, a 200 study published in the Journal of the Royal Society of Medicine reports that nettle leaf can reduce osteoarthritic pain in the base of the thumb when applied to the painful area.

Although no official studies have been done as of yet regarding the affect of nettle on weight loss, the herb with its cleansing properties may help shed the pounds by effectively ridding the body of unwanted metabolic waste.

Herbal teas help increase fluid intake, while often decreasing the consumption of unhealthy drinking alternatives, such as sugar sweetened beverages. A 2010 article in Journal of Nurse Practitioners agrees that herbal teas can enhance weight loss and aid in making positive dietary choices.

Read more: 6 Surprising Ways to Cook With Tea

In a 2014 Iranian Journal of Reproductive Medicine study regarding the negative effects of nicotine on sperm in mice, researchers discovered that increasing the dose of nettle "significantly boosted motility, count, normal morphology of sperm cells, seminiferous tubules diameter, and testosterone in all groups compared to control."

There have been no studies to verify the effects of nettle on human testosterone levels, but the animal studies show promise. A 2015 study published in Veterinary Research Forum, found that nettle was successful in increasing serum testosterone levels in rats. Nettle root extract inhibits an enzyme that reduces testosterone levels, thus retaining more in the body.

Nettle tea has been touted for its healing properties and, in fact, a 2014 study in African Journal of Traditional, Complementary and Alternative Medicines concluded the effectiveness of nettle extract mixed with methanol as a natural antimicrobial agent for use against strong pathogens. A 2012 study published in Acto Periodica Technologica indicated weak, but present antibacterial properties of nettle extract.

Common in most temperate regions along rivers and lakes, stinging nettle is a plant may also have anti-fungal properties. A 2011 study published in Applied Microbiology and Biotechnology indicates that certain plants contain lectins, compounds that exhibit anti fungal effects. Nettle is one of those plants that contains lectins that inhibit the growth of fungus.

You can buy stinging nettle supplements in several forms, including dried leaf, tincture and extract. Nettle creams also are available, but typically are used for treating dermatological conditions. The book Integrative Medicine indicates the typical dosage of nettle as 300 to 350 milligrams of the freeze-dried extract up to three times a day.

The recommended dose for a nettle supplement depends on the type of supplement you prefer and for which type of condition. A doctor can help guide you on the proper dosage for your individual needs.

Nettle tea is made all around the world and is easy to do. A 2012 article published in The Scientific World Journal speculates that fresh nettles may have more nutrients than dried. If you have fresh young nettle leaves, use caution when handling, as they can cause irritation to the skin. Boil 1 cup of fresh nettle leaves in 2 cups of boiling water. Allow it to steep for 10 minutes and strain out the leaves.

In his book Identifying and Harvesting Edible and Medicinal Plants, wild foods author Steve Brill cautions amateur foragers that late-season nettle leaves may contain compounds harmful to the kidneys; gather leaves before they flower.

"All use should be supervised and approved by a physician," says naturopathic doctor Robert Kachko. "Some people can be allergic to nettles, so start with a very low dose," he says. It may also interact with some drugs including blood thinners, lithium, NSAIDs and drugs for high blood pressure and diabetes. Don't take if you're already on diuretics, as nettle can increase water loss. There have also been reports of gastrointestinal issues associated with excess nettle consumption, including diarrhea.

Nettle tea is also "contraindicated in pregnancy," says Dr. Kachko. It can cause the uterus to contract and may contribute to miscarriage, according to 2007 research in Toxicology and Applied Pharmacology. Dr. Kachko also warns that people with heart disorders, kidney problems or hormone-mediated cancers should use caution. Lastly, because of its effects on hormones, it shouldn't be consumed by children.

Have you ever tried nettle tea? What did you think? Or have you tried nettle leaves in some other form? Did it help alleviate any of your physical ailments? What do you think about the research that's being done on stinging nettle and nettle tea? Share your thoughts and questions in the comments below!