Common Names
- Stinging nettle
- Common nettle
- Greater nettle
For Patients & Caregivers
How It Works
Nettle was shown effective in relieving symptoms of benign prostatic hyperplasia (BPH), and osteoarthritis.
Nettle is a perennial herbaceous flowering plant, native to Asia, Europe, and North America. The root is widely used to treat benign prostatic hypertrophy (BPH), allergies, arthritis, and inflammation. Nettle is usually combined with herbs such as saw palmetto and pygeum for the treatment of BPH.
Data from clinical studies indicate benefits of nettle in the treatment of osteoarthritis of hip, knee, hand, gonarthritis, and in relieving symptoms associated with benign prostatic syndrome (BPS). A combination of saw palmetto and nettle greatly improved nocturnal voiding frequency compared to placebo, and was similar to tamsulosin or finasteride in patients with moderate to severe lower urinary tract symptoms (LUTS)/BPH. Nettle was shown to improve glycemic control in type-2 diabetic patients. It also showed anticancer effects in laboratory studies, but clinical trials have yet to be conducted.
Purported Uses
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To treat allergies
Evidence is lacking to support this claim. -
To treat arthritis
Clinical trials support the topical use of nettle for arthritis of the hip, knee, and hand. Larger studies are needed to confirm these data. -
To treat benign prostatic hypertrophy (BPH)
When combined with other herbs, nettle has shown positive results in clinical trials. -
To clear up chest congestion
Evidence is lacking to support this claim. -
To reduce inflammation
Nettle may have anti-inflammatory activities, but clinical trials have yet to be conducted. -
To calm muscle spasms
Evidence is lacking to support this claim. -
To treat urinary tract disorders and relieve difficult or painful urination
Nettle was shown to have beneficial effects in clinical studies.
Do Not Take If
Side Effects
- A case of enlarged breasts has been reported in a man following consumption of nettle tea.
- Nipple discharge was reported in a woman after ingestion of nettle tea.
- A breastfed, 17-day-old infant developed hives following the mother’s use of water boiled with stinging nettle to heal nipple cracks.
- Low blood sugar was reported in a 78-year-old man after taking an herbal remedy containing nettle for benign prostatic hypertrophy.
- Allergic rhinitis has been reported in 2 patients following exposure to nettle pollen
For Healthcare Professionals
Clinical Summary
Nettle is a perennial herbaceous flowering plant, native to Asia, Europe, and North America. The root is widely used to treat benign prostatic hypertrophy (BPH), allergies, arthritis, and inflammation. Nettle is usually combined with herbs such as saw palmetto and pygeum for the treatment of BPH. Several compounds have been isolated from nettle including flavonoid glycosides that appear to contribute to its biological effects, although the precise mechanism of action is unclear. In vitro and animal studies indicate that nettle extract has reno- (1) and hepatoprotective (2) properties, and is effective against colitis in mice (3).
Data from clinical trials suggest benefits of nettle in the treatment of osteoarthritis of hip, knee (4) hand (5) , gonarthritis (20), and in ameliorating symptoms associated with benign prostatic syndrome (BPS) (6) (7) (8). A combination of saw palmetto and nettle was reported to affect significant improvements in nocturnal voiding frequency compared to placebo, and was similar to tamsulosin or finasteride, in patients with moderate to severe lower urinary tract symptoms/BPH (21). In another study nettle was shown to improve glycemic control in type-2 diabetic patients (9).
Nettle was also shown to have anti-proliferative effects in prostate cancer cells (10); to protect against cisplatin-induced toxicity (11); to enhance the sensitivity of breast cancer cells to paclitaxel (22); and to increase cisplatin cytotoxicity in non-small cell lung cancer cells (23).
Purported Uses
Mechanism of Action
In vitro studies show that nettle extract inhibits several inflammatory events that are responsible for the symptoms of seasonal allergies (2). They include the antagonist and negative agonist activity against the histamine-1 (H1) receptor, and inhibition of prostaglandin formation via inhibition of cyclooxygenase-1 (COX-1), cyclooxygenase-2 (COX-2), and hematopoietic prostaglandin D2 synthase (HPGDS), which are key enzymes in pro-inflammatory pathways (2).
Phenolic compounds derived from nettle were shown to inhibit alpha-glucosidase and alpha-amylase, chief enzymes involved in type-2 diabetes (24). Inhibition of these enzymes results in decreasing the reabsorption of glucose in the intestine.
A number of compounds in essential oil derived from nettle including carvacrol may have cytotoxic and genotoxic effects (12). And a methanolic extract of nettle was found to reduce experimentally induced prostatic hyperplasia in mice (17).
Adverse Reactions
- A case of gynecomastia was reported in a man following consumption of nettle tea (15).
- Galactorrhea was reported in a woman after ingestion of nettle tea (15).
- A breastfed, 17-day-old infant developed urticaria following the mother’s use of water boiled with stinging nettle to heal nipple cracks (16).
- Hypoglycemia was reported in a 78-year-old man after taking an herbal remedy containing nettle for benign prostatic hypertrophy (17).
- Allergic rhinitis has been reported in 2 patients following exposure to nettle pollen (25).
- Two adults who were severely stung following contact with Australian nettle tree required ICU admission. It took 2–3 weeks for them to return to normalcy, with urticaria and pain continuing for several months (26).
Herb-Drug Interactions
- Cytochrome P450 substrates: Nettle inhibits cytochrome P450 enzymes and may affect the intracellular concentration of drugs metabolized by these enzymes (18).
- Diuretics: Theoretically nettle may have an additive effect due to its diuretic activity (19).
- Hypotensives: Nettle has hypotensive action and may enhance the effects of hypotensive drugs (19).