Nettle is a flowering plant found in the temperate regions of Europe and Asia as well as South Africa and Australia. It is also known by the names of Stinging Nettle, Common Nettle, Net Plant, and Devils Leaf. The whole plant is covered with sharp, hollow spines that contain an acrid fluid that can cause skin irritation and inflammation. The sting of a Nettle may can be relieved by rubbing the skin with the fresh-cut leaves of rosemary, mint, or sage. Nettle contains high amounts of iodine, which makes it nourishing for the thyroid gland, which is the body's "internal thermostat." Nettle also is rich in Vitamin A and Vitamin C, iron, calcium, magnesium, potassium, and chlorophyll. Primary chemical constituents found in stinging nettle include formic acid, betaine, histamine, acetylcholine, glucoquinone, chlorogenic acid, mucilage, tannin, silica, beta carotene, calcium, iron, chlorophyll, and choline. Polysaccharides (complex sugars) and lectins (large protein-sugar molecules) are probably the most active constituents.

Nettle has a long history of use dating back to ancient Greece. A popular herb for men's health, nettle nourishes the kidneys and the urinary tract. It has been used to treat coughs, tuberculosis, and arthritis. The leaf has been shown to prevent the body from making inflammatory chemicals known as prostaglandins. Nettle's root affects hormones and proteins that carry sex hormones (such as testosterone or estrogen) in the human body. These may explain why this herb is sometimes recommended as an herbal treatment for benign prostatic hyperplasia. Throughout Europe, stinging nettles are used as a spring tonic and general detoxifying remedy that has been successful in treating some cases of rheumatism and arthritis. The leaves are considered a blood purifier. As an astringent, nettles may be used to treat nosebleeds or any other hemorrhage in the body. Traditional herbalists use nettle tea to bring back the natural color of hair. Known topical applications for this herb include use as a shampoo, conditioner, and hair rinse for dandruff, and for stimulation of hair growth and prevention of hair loss. It is also an astringent cleanser for oily skin.

Using nettle tea to water garden plants may stimulate their growth and make them more resistant to bugs. Plants growing close to nettle tend to contain stronger volatile oils. When added to the compost pile, nettle hastens breakdown. Nettle stalks are strong and can be woven to make sails or twine. When lactating animals are fed nettles, they may produce more milk; chickens fed nettles are said to produce more eggs.