Nettle is both an edible and healing plant. Even if in some countries it is used only rarely, it’s one of the most important herbs of the Western tradition.
Many species exist around the world, and most of them have stinging hairs. Some of the most known species are U. dioica (dioecious) and U. urens (monoecius).
Rich in proteins and minerals (among which Ca, K, Si, Mg, Fe, P), nettle can be defined as a nutritive tonic and an alterative (that is, it “alters” metabolism so to remove the causes of toxin accumulation) with slightly stimulant properties.
Its action is complex, and it strongly affects the whole metabolism, the reactivity of immune system and skin, the liver and pancreas activities and the renal function.
It has a bivalent action on fluids, since:
- it eliminates excess fluids, through its diuretic, anti-edema (the fresh plant juice has proven effective on cardiac edema too), emmenagogue and slightly laxative (as a decoction, or cooked with clams [Mattioli]) actions, and, at the same time
- it reduces fluids loss, through its anti-enuretic, hemostatic (for hemoptysis, hematuria, metrorrhagia, epistaxis) and anti-diarrheal actions.
Nettle stimulates biliary, pancreatic and enteric secretions, improving digestion (according to some authors, this action is also due to small amounts of secretin contained in the plant).
Due to the significant amount of minerals it contains, it has remineralizing and anti-anemic properties, being able to both increase the blood iron content and to stimulate the production of red cells. The anti-anemic action is due, according to some authors, to the combined action of the iron contained in the plant (that is not really that abundant), and chlorophyll, a molecule that is chemically strictly related to heme.
Immune system and skin reactivity
Even though it has a stimulating action upon the immune system (indeed it tonifies the melancholic component of blood), nettle is able to reduce allergic reactions (in this case, the most effective form is the freeze-dried plant powder) and to stimulate the elimination of the mucus produced during such reactions.
It’s indicated in itching and burning dermatitis.
Nettle has a strong hepatoprotective action and probably it optimizes the hepatic production of proteins: indeed, in some animal testing it increased the biosynthesis of albumin or it resolved its decreasing in blood due to hepatotoxicity, positively influencing prognosis. This property helps nettle to “keep” plasma within vessels and possibly also helps it to reduce edema and resolve low blood pressure (upon which it acts as a specific remedy, according to some authors).
Traditionally used in diabetes, several studies confirm its efficacy: it decreases intestinal glucose absorption and increments its uptake by hepatocytes, decreases insulin resistance at the level of the skeletal muscles cells and exerts a general anti-inflammatory systemic action. According to some studies, it promotes the regeneration of the pancreas beta islets.
Nettle stimulates the renal function by tonifying and supporting the kidneys; the whole plant is considered a kidney trophorestorative, and the seeds are deemed the most active part. It has a protective action on kidneys in case of ingestion of toxic substances.
It is diuretic (especially increasing diuresis when it’s lower than normal) and natriuretic (according to a single study, without affecting potassium excretion significantly), uricolytic (it eliminates urates coming from the protein metabolism, so being indicated for arthritis, gout, tissue acidity), antilithic (it prevents urinary stones and gravel formation and promotes their elimination).
It’s indicated in cystitis, especially when abundant mucus is produced.
Traditionally used in some countries to treat hypertension, nettle has a bivalent action upon blood pressure, supporting it when it is low (possibly with fainting on rising) and reducing it when high. So, it is useful in both conditions.
It’s able to restore underactive functions and organs, exercising a normalizing action on kidney, thyroid, heart, nerves and proving useful in case of menstrual difficulties, hormonal deficiencies, muscle atrophies. It increases the production of milk and treats male impotence. It has a certain effectiveness in hair loss and discoloration of the hair. In particular, it proves useful:
- in case of functional deficits after anesthesia;
- during the pregnancy (it tonifies the pelvic and thigh muscles, promoting childbirth);
- agalactia (post-partum);
- mental dullness, lack of concentration and mental acuity [Wood].
It has an emmenagogue action, so it helps with amenorrhea and dysmenorrhea, but acting also on metrorrhagia, stopping the excessive bleeding.
Traditionally used for “urtication”, that is, the practice of beating the skin with fresh nettle shoots on the zones affected by rheumatisms, gout, and paralysis.
It has a simil-digitalic cardiotonic action upon frog heart in situ and isolated (Garello Cantoni, 1939).
It has an antihemorrhagic action, working in a bivalent manner, both as a vasoconstrictor and a vasodilator.
The root soothes the inflamed glands (external use) and acts on the prostate affected by BPH.
It heals the skin and internal wounds and ulcerations. It also works on gangrenous sores, purulent and hard-to-heal wounds.
It has an anti-inflammatory action upon the small and large intestines, dampening any possible irritation. It also has an antispastic and bivalent antidiarrheal and slightly laxative action. It treats colitis.
It mitigates chronic cough and treats asthma.
It promotes the expulsion of the thick and sticky dampness.
It mitigates joint pains in case of gout, rheumatisms and joint inflammation.
The seeds have, in particular, an anti-enuretic (they treat bedwetting) and an expectorating functions; they are indicated in case of cough (Dioscorides recommends them macerated with honey in wine).
They restore the renal function and prove really useful on chronic kidney insufficiency. Several times, their use allowed to avoid dialysis. In this case, the seeds are collected when still unripe and dried or tinctured.
Nettle is plant endowed with a lot of properties that can be summed up as follows:
- it restores metabolism and atrophied functions;
- it nourishes and optimize the nutritive function;
- it’s a restorative tonic (a property that follows from the two above);
- it “contains” (it’s hemostatic, anti-asthenic, anti-diarrheal);
- it’s purifying (it eliminates waste products: diuretic, uricolytic, lymphatic, slightly laxative);
- it’s anti-inflammatory.
For all these reasons, it’s an extremely versatile herb, so much that David Hoffman, known Medical herbalist, says: “When in doubt, give nettle”.
[Mattioli] Pietro Andrea Mattioli, “Discorsi di M. Pietro Andrea Mattioli sanese, medico cesareo, ne’ sei libri di Pedacio Doscoride Anazarbeo della materia Medicinale” (1746)
[Durante] Castore Durante, “Herbario Nuovo” (1667)
[Wood] Matthew Wood, “The Earthwise Herbal – A Complete Guide to Old World Medicinal Plants”, North Atlantic Books (2009)