Stinging Nettle

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Stinging Nettle (Urtica dioca)
  Evaluated for:
Effectiveness Rating Effectiveness Rating
Benign prostatic hyperplasia (BPH)
+1 (Slight Evidence)
Allergic Rhinitis
+1 (Slight Evidence)


  • Stinging nettle is a perennial plant used as a medicinal agent since ancient times. Although very nutritious, its leaves and stems are covered with painful, stinging hairs. Before eating, nettles must be steamed or cooked to destroy the stinging hairs. Contact with the hairs leads to a very painful sting, with itching or numbness that last up to days. Luckily, medicinal extracts of stinging nettle do NOT cause this reaction as the stinging hairs are destroyed during processing.
  • An extract of stinging nettle roots reduced levels of an enzyme called 5-α-reductase. When administered along with weak to moderate aromatase inhibitors, this enzyme played a key role in treating benign prostate hypertrophy (BPH) in rats. Aromatase converts androgens (primary male hormones) into estrogens (primary female hormones), which also appears to play a role in the development of BPH. Several double-blind human trials of stinging nettle root extract showed a benefit for patients with lower urinary tract symptoms caused by BPH.
  • Like over-the-counter and prescription antihistamines, nettle extract blocks the histamine-1 receptors that cause allergies.


  • Nettle is hard to find by itself for treating BPH. It is usually combined with other dietary supplements, such as saw palmetto, to treat this condition.
  • On rare occasions, fresh nettle has caused a severe allergic reaction.
  • Nettle supplements may interact with blood thinners (e.g., coumadin) and antiplatelet agents (e.g., aspirin, clopidogrel) and increase the risk of bleeding or clotting.
  • When used to treat BPH, aromatase inhibition by nettle can theoretically increase abdominal fat stores. This is thought to be related to decreased estrogen levels.


  • Pregnant patients should not use stinging nettle for allergic rhinitis as may cause premature uterine contractions.
  • Nettle may interact with alpha-blocker BPH medications such as prazosin, doxazosin and terazosin to cause a sudden drop in blood pressure.
  • Stinging nettle may increase the risk of bleeding or clotting in patients on prescription blood thinners.

DOSAGE: Doses from 100 to 200 mg, 2-3 times daily, showed positive effects in the prevention and management of allergies.

CONCLUSION: If you elect to try Stinging Nettle, remember to include it in your list of medications when you visit your doctor and other health care providers.

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