Nettle is the common name for any of between 30-45 species of flowering plants of the genus Urtica in the family Urticaceae, with a cosmopolitan though mainly temperate distribution. They are mostly herbaceous perennial plants, but some are annual and a few are shrubby.
A tasty green food your body recognizes, the “stinging nettle” (Urtica dioica or urens) is a weed native to Europe, Asia, as well as North America. (Various unrelated plants are sometimes also called nettles -- the Old World nettle trees of the elm family, and the prickly horse nettle of the nightshade family) The shoots grow from two to three feet, to as high as 10', and flourish in soils that are high in nitrogen. All nettles sting, but thankfully their stinging properties disappear once they've been dried or cooked. As they are used throughout Europe, nettles make a valuable tonic after the long winter months because they provide a potent natural source of a number of vitamins and minerals. Formic acid ("fire ants" use this to sting you) in nettle leaves is what makes them sting, along with histamine. (Ironically, though, they're useful in combating allergies).
Nettles enjoy a rich folkloric history both general (as a spring tonic) and specific. Among the more esoteric uses: as a cure for baldness, bedwetting (eaten in cakes), an aphrodisiac (seeds mixed into jam), and as a cure for fear (when held in the hand, along with a sprig of yarrow). Urtication-the process of flailing yourself with nettles -- originally introduced to England by Roman soldiers who thought they'd need to do it to keep warm -- is a folk practice still used today by people suffering from arthritis and even M.S. By deliberately applying stinging nettles to their skin, it provokes inflammation. Through this process, the pain of the sufferers is relieved temporarily.
For many, consuming nettles raw, cooked in soup, as tea, salad or in capsule form, has become a springtime tradition, hence nettles association with spring time. It is a form of cleansing which for some consumes the phlegmatic superfluities which winter has left behind.
Nettles are fantastically high in vitamins A and C, and rich in nutrients, including calcium, choline, magnesium, boron, iron, iodine, silica, sulfur, potassium, chlorophyll, histamine, serotonin, glucoquinones, bioflavonoids, tannins and amino acids. They're unusually high in protein (40%) for a plant. And because they're so nutrient-dense, they make a good overall tonic for strengthening the body and an effective traditional treatment for scurvy.
It is also believed to be a “galactagogue” (an agent that promotes the secretion and flow of milk), and a clinical trial has shown that its juice is diuretic in patients with congestive heart failure. Nettle extract is also useful in treating anemia, their high vitamin C content helps ensure that the iron is properly absorbed by the body. Besides anemia, the extracts can also be used to treat hay fever and kidney problems.
Fresh nettle, specifically Urtica Dioica, is used in folk remedies to stop all types of bleeding, due to its high Vitamin K content. Meanwhile, in dry Urtica Dioica, the Vitamin K is practically non-existent, and so is used as a blood thinner.
Nettle is used in hair shampoos to control dandruff, and is said to make hair more glossy, which is why some farmers include a handful of nettles with cattle feed. Stories during the 1800s about fraudulent practices of some horse peddlers in Europe include using 1-2 handfuls of nettle seed a day mixed to their horses’ feeds for two weeks which would explain its unexplainably shiny pelts and youthful appearance when they take it to the market. Of course, this gave them the reason to sell it in a handsome price and it did get sold. The youthfulness of course disappeared once the animals got to their new homes - no nettle seed.
Amongst its many properties, the nettle’s extract has lately been shown to influence prostate health and prevention of prostate conditions, especially prostatitis, which is an inflammation of the prostate gland. Nettle root extracts have been extensively studied in human clinical trials as a treatment for symptoms of benign prostatic hyperplasia (BPH). These extracts have been shown to help relieve symptoms compared to placebo both by themselves and when combined with other herbal medicines.
A highly concentrated extract from the nettle root provides a unique mechanism for increasing levels of free testosterone. Recent European research has identified constituents of nettle root that bind to SHBG (sex hormone binding globulin) in place of testosterone, thus reducing SHBG's binding of free testosterone. As the authors of one study state, these constituents of nettle root "may influence the blood level of free, i.e. active, steroid hormones by displacing them from the SHBG binding site." Due to this, body builders have been using certain extracts of nettle in an effort to increase free testosterone by occupying sex-hormone binding globulin.
Nettle’s aphrodisiac effect was perhaps due to its ability to increase free testosterone. Free testosterone stimulates sex cell receptor sites in the brain hence an increase of sexual response and functions for both men and women. Furthermore, its richness in nutrients and other essential vitamins and minerals enhance the workings of one’s overall health thus minimizing the other health conditions that inhibit proper sexual functions. Additionally, nettle extract is also believed to work as an adaptogen. It helps with the general stress response, they strengthen the adrenals, and they're loaded with minerals and trace elements.