What the evidence says. Graded moderate: several double-blind RCTs and a meta-analysis show real but modest benefit of root extract for BPH urinary symptoms, and small diabetes trials plus a meta-analysis show lower fasting glucose and HbA1c. Most trials are small, short, single-country (largely Iranian) and not independently replicated, so confidence is limited. (Moderate evidence: Several controlled trials; effects real but modest or context-dependent.)
What is Stinging Nettle?
Stinging Nettle (Urtica dioica) is a joint and skin supplement used for ease bph urinary symptoms. NutriDex grades the human evidence as Moderate. Stinging nettle is used in two distinct ways: the root for benign prostatic hyperplasia (BPH) and the leaf for blood sugar, allergies and joint pain. The best evidence is for root extract in BPH: a 6-month double-blind RCT in 620 men cut symptom scores from ~19.8 to 11.8 (vs little change on placebo), and a meta-analysis of 5 trials (~1,128 men) found improved symptom scores and urinary flow without affecting PSA. In type 2 diabetes, small RCTs and a meta-analysis report lower fasting glucose (about -17 mg/dL) and HbA1c (about -0.9%), usually added to standard drugs. Topical nettle 'sting' modestly reduced thumb-joint osteoarthritis pain in a small crossover trial. Allergic-rhinitis results are weak, with placebo improving similarly. Trials are mostly small, short and concentrated in a few centres, so effects are promising but not definitive.
Purported Benefits
✓Ease BPH urinary symptoms
✓Lower blood sugar (adjunct)
✓Relieve joint pain (topical)
✓Hay-fever symptom support
Evidence by outcome
The same supplement can be well-proven for one use and unproven for another — here is the human evidence graded outcome by outcome.
Outcome
Evidence
Effect
Studies
Ease BPH urinary symptomsRoot extract cut IPSS in a 620-man RCT and a 5-trial meta-analysis; centers are few and PSA unchanged.
Moderate
↑ benefit · moderate
3
Lower blood glucose / HbA1cMeta-analysis shows lower fasting glucose and HbA1c, but as an add-on to standard drugs in small trials.
Oral root and leaf extracts are generally well tolerated; the main side effects are mild GI upset, headache, nausea and occasional fluid changes (nettle is a mild diuretic). Because nettle can lower blood glucose and blood pressure, it may add to antidiabetic drugs (risk of hypoglycemia) and antihypertensives; its vitamin K content and diuretic action could affect warfarin and lithium handling, so monitor if you take these. Fresh leaf contact causes a transient stinging rash, and use in pregnancy/breastfeeding is not established and best avoided. Men should not self-treat prostate symptoms with nettle without ruling out cancer first. Educational only — always check with your doctor or pharmacist before combining Stinging Nettle with any medicine.
Stinging Nettle drug interactions
Known or theoretical interactions between Stinging Nettle and common medications — educational, not exhaustive. Always check with your doctor or pharmacist before combining Stinging Nettle with any medicine.
Stinging Nettle is most often taken for Ease BPH urinary symptoms, Lower blood sugar (adjunct), Relieve joint pain (topical), Hay-fever symptom support. Root for prostate symptoms; leaf studied for joints and blood sugar.
Does Stinging Nettle work — what does the evidence say?
Moderate evidence. Several controlled trials; effects real but modest or context-dependent. Stinging nettle is used in two distinct ways: the root for benign prostatic hyperplasia (BPH) and the leaf for blood sugar, allergies and joint pain. The best evidence is for root extract in BPH: a 6-month double-blind RCT in 620 men cut symptom scores from ~19.8 to 11.8 (vs little change on placebo), and a meta-analysis of 5 trials (~1,128 men) found improved symptom scores and urinary flow without affecting PSA. In type 2 diabetes, small RCTs and a meta-analysis report lower fasting glucose (about -17 mg/dL) and HbA1c (about -0.9%), usually added to standard drugs. Topical nettle 'sting' modestly reduced thumb-joint osteoarthritis pain in a small crossover trial. Allergic-rhinitis results are weak, with placebo improving similarly. Trials are mostly small, short and concentrated in a few centres, so effects are promising but not definitive.
What is the typical dose of Stinging Nettle?
Root extract ~300–600 mg/day (or 600–1200 mg dried root) for prostate symptoms; leaf extract ~500 mg three times daily studied for blood sugar.
Is Stinging Nettle safe? Any cautions or side effects?
Oral root and leaf extracts are generally well tolerated; the main side effects are mild GI upset, headache, nausea and occasional fluid changes (nettle is a mild diuretic). Because nettle can lower blood glucose and blood pressure, it may add to antidiabetic drugs (risk of hypoglycemia) and antihypertensives; its vitamin K content and diuretic action could affect warfarin and lithium handling, so monitor if you take these. Fresh leaf contact causes a transient stinging rash, and use in pregnancy/breastfeeding is not established and best avoided. Men should not self-treat prostate symptoms with nettle without ruling out cancer first.
How many studies support Stinging Nettle?
NutriDex cites 11 sources for Stinging Nettle, graded "Moderate".
Does Stinging Nettle interact with any medications?
Yes — known or theoretical interactions include: Blood thinners (warfarin, DOACs) (caution). This is educational and not exhaustive; always check with your doctor or pharmacist before combining Stinging Nettle with any medicine.
Cite this page
APA
Peh, D. (2026). Stinging Nettle (Urtica dioica): Benefits, Dosage, Side Effects & Evidence. NutriDex — The Supplement Research Compendium. Retrieved 16 Sept 2026, from https://nutridex.info/s/nettle
BibTeX
@misc{nutridex_nettle,
author = {Peh, Daryl},
title = {Stinging Nettle (Urtica dioica): Benefits, Dosage, Side Effects \& Evidence},
year = {2026},
howpublished = {NutriDex --- The Supplement Research Compendium},
url = {https://nutridex.info/s/nettle},
note = {Reviewed by Dr Daryl Peh, MBBS Singapore, MMed FM. Accessed 2026-09-16}
}
For medical claims, citing the underlying primary studies linked above is preferred. NutriDex is an educational reference, not medical advice.