Stinging Nettle

Urtica dioica · Nettle root · Nettle leaf

Snapshot

Indications	Contraindications
Benign prostatic hyperplasia^{1, 2} Type 2 diabetes glycemia^3–5 Osteoarthritis pain⁶ Minor urinary complaints⁷	Hypersensitivity to nettle⁷ Fluid-restricted cardiac disease⁷

Stinging nettle (Urtica dioica) is a perennial herb native to Asia, Europe, and North America, used as root and leaf extracts⁸. In vitro, the extract inhibits cyclooxygenase enzymes in prostaglandin pathways⁸. Supplementation follows from that anti-inflammatory activity: root extract for urinary symptoms of benign prostatic hyperplasia (BPH), leaf extract for osteoarthritis pain and glycemic control in type 2 diabetes, and allergy relief, where evidence is lacking⁸. Typical patients are older men with urinary symptoms and adults with osteoarthritis or type 2 diabetes.

For BPH, a 12-month placebo-controlled trial of a root extract found improved symptom scores¹, while a 2000 systematic review found no convincing evidence for nettle alone⁹. In type 2 diabetes, meta-analyses found lower fasting glucose, with high heterogeneity^{3, 4}. In rats, a 2024 study found a root extract regressed testosterone-induced prostate enlargement; no human trial has tested that extract¹⁰. Products listing nettle include liquid extracts and capsules; see Form comparison.

The fluid-related contraindication reflects nettle's diuretic use: the European herbal monograph lists conditions requiring reduced fluid intake, such as severe cardiac or renal disease, as a contraindication for traditional use⁷. Memorial Sloan Kettering lists possible additive effects with diuretics and blood pressure medications, based on animal data of undetermined clinical relevance⁸.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

58 sources, 45 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources