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📰Read the full Stinging Nettle evidence review on GMJ News →Complete clinical article, references and updates on news.gmj.ge. This page is the structured safety summary.⚠ Patient buying nettle LEAF for prostate symptoms — needs ROOT extract [1]
⚠ Patient on warfarin consuming nettle leaf (high vitamin K1) — monitor INR [1]
⚠ Patient on lithium adding nettle (diuretic) — lithium toxicity risk [1]
⚠ Pregnant patient taking nettle ROOT — contraindicated due to hormonal effects [1]
ℹ️ Not obtained from food. Not applicable — this is not obtained from food in meaningful amounts; supplementation is the practical route.
🔬 Lab interpreter
Recommended test
PSA (if using for BPH)
PSA (if using for BPH)
Reference range / target
Age-appropriate reference ranges
Age-appropriate reference ranges
Unlike finasteride, nettle root does NOT artificially reduce PSA — no need for the 'multiply by 2' correction [2].
Full lab monitoring ↓⚕ For professionals — confirm ranges against your local laboratory.
Clinical verdict
Root ≠ Leaf is the single most important teaching point. Root (aromatase/SHBG/5α-reductase) for BPH — Level I evidence when combined with saw palmetto (non-inferior to finasteride, n=620). Leaf (flavonoids/anti-inflammatory) for allergies/joints — weaker evidence. Patients frequently confuse the two. Nettle soup ≠ nettle root extract [1] [2].
1 How much do I need?
👤 Adults: Specific dosage data under clinical review
👴 Elderly: Specific dosage data under clinical review
🤰 Pregnancy: See guidance
Nettle LEAF tea used traditionally as nutritive tonic in pregnancy (limited safety data). Nettle ROOT contraindicated in pregnancy due to aromatase inhibition and SHBG binding [1].
👦 Pediatric: See guidance
Nettle leaf tea has been used traditionally in children for nutritional support. No established pediatric dosing for medicinal extracts [1].
🏃 Athletes: Standard dose
⚖️ Obesity: Standard dose
Fat-soluble compounds may require dose adjustment in obesity.
🩺 Renal: Consult specialist
Dose adjustment may be needed in renal impairment.
🌱 Vegan: Standard dose
How to take
🍽 Timing: Root extract: twice daily with meals. Leaf: 2–3×/day. For allergies, start at onset of allergy season [1].
💊 With food: Take with food to reduce GI upset [1].
🚫 Avoid: Confusing root and leaf indications. Nettle root in pregnancy. Nettle leaf in patients on warfarin without INR monitoring [1].
2 Which form?
| Form | Bioavailability | Vegan | Cost |
|---|---|---|---|
| ['Nettle root extract (standardized)', 'preferred for BPH', 'Standardized to β-sitosterol or lignan content. Used in BPH clinical trials. 120 mg 2–3×/day [1].'] | Standard | Check label | |
| ['Nettle leaf extract', 'preferred for allergy/inflammation', 'Freeze-dried leaf or standardized extract for allergic rhinitis. 300 mg 2–3×/day [1].'] | Standard | Check label | |
| ['Nettle root + saw palmetto combination', 'clinical', 'Most-studied combination for BPH. PRO 160/120 (Prostagutt®) used in the landmark n=620 trial [2].'] | Standard | Check label | |
| ['Dried nettle leaf tea', 'traditional', "Traditional diuretic ('spring tonic'). Modest effect. 2–4 cups/day [1]."] | Standard | Check label | |
| ['Fresh nettle greens (cooked)', 'culinary', 'Rich in iron, calcium, and vitamin K. Stinging compounds destroyed by cooking [1].'] | Standard | Check label |
3 Common questions
Root or leaf — which should I take? ▼
They are different medicines. ROOT is for BPH/prostate/urinary symptoms — it contains aromatase inhibitors and SHBG-binding compounds. LEAF is for allergies, inflammation, and nutritional support — it contains flavonoids and anti-inflammatory compounds. Using the wrong part for your condition will not work [1].
Is nettle root + saw palmetto as good as finasteride? ▼
In the largest head-to-head trial (n=620, 48 weeks), the combination (Prostagutt® forte) was non-inferior to finasteride 5 mg on IPSS scores, with significantly fewer sexual side effects. However, this was one trial with a specific branded product. Individual results may vary [2].
Can I just eat nettle soup for prostate health? ▼
No. Cooked nettle greens are nutritious but do not contain the standardized root compounds (β-sitosterol, lignans) at therapeutic concentrations. Medicinal use requires standardized root extract, not culinary leaf preparations [1].
Is stinging nettle safe for allergies? ▼
Freeze-dried nettle leaf (300 mg, 2–3×/day) has one double-blind RCT showing subjective improvement in allergic rhinitis. It is generally safe with mild side effects. However, evidence is limited — it should not replace proven antihistamines for moderate-severe allergies [1].
4 Clinical evidence
Strong
BPH/LUTS: a randomized, double-blind trial (n=620) over 48 weeks compared nettle root (120 mg) + saw palmetto (160 mg) twice daily with finasteride 5 mg/day. The combination was non-inferior to finasteride on IPSS (International Prostate Symptom Score) with significantly fewer sexual side effects [2]. HIGH
Moderate
Allergic rhinitis: a randomized, double-blind trial (n=69) of freeze-dried nettle leaf (300 mg) showed 58% of participants rated it effective vs 37% for placebo (subjective rating, no objective endpoints) [1]. BPH (monotherapy): meta-analysis of 3 smaller RCTs of nettle root alone showed modest IPSS improvement vs placebo [1]. Anti-inflammatory (leaf): one RCT found 1,340 mg/day nettle leaf reduced NSAID requirement in osteoarthritis patients [1]. MODERATE
Insufficient
5 Safety, toxicity & adverse events
Relative
⚠ Concurrent antihypertensives — nettle has mild diuretic effect
⚠ Concurrent diabetes medications — may enhance hypoglycemia
⚠ Concurrent anticoagulants — vitamin K content in leaf preparations
⚠ Concurrent sedatives — root extract may have mild CNS depressant effects
⚠ Pregnancy — traditional uterotonic concern (though leaf tea is used historically)
🚩 Red flags
● Patient self-treating urinary symptoms with nettle root without urological evaluation — rule out prostate cancer first [2]
● Patient on warfarin adding nettle leaf — high vitamin K1, monitor INR [1]
● Patient on lithium starting nettle — diuretic effect may increase lithium levels [1]
6 Interactions
Drug interactions
Warfarin Moderate
Mechanism: Nettle leaf is rich in vitamin K1; antagonizes warfarin effect [1].
Effect: Decreased INR, reduced anticoagulation [1].
Action: Monitor INR. Keep nettle leaf intake consistent if using [1].
Lithium Moderate
Mechanism: Nettle's diuretic properties may reduce renal lithium clearance [1].
Effect: Potential lithium toxicity (tremor, nausea, renal) [1].
Action: Monitor serum lithium levels if adding nettle [1].
Supplement synergies
Saw Palmetto · Nettle root 120 mg + saw palmetto 160 mg, both 2×/day
Synergistic for BPH: nettle root (aromatase/SHBG) + saw palmetto (5α-reductase). Best-studied combination (n=620 trial) [2].
Synergistic for BPH: nettle root (aromatase/SHBG) + saw palmetto (5α-reductase). Best-studied combination (n=620 trial) [2].
Quercetin · 500 mg quercetin + 300 mg nettle leaf
Complementary anti-allergy mechanisms. Quercetin stabilizes mast cells; nettle leaf reduces histamine response [1].
Complementary anti-allergy mechanisms. Quercetin stabilizes mast cells; nettle leaf reduces histamine response [1].
7 Regulatory
Germany (Commission E): Nettle root: approved for BPH (stages I–II). Nettle leaf: approved as supportive treatment for rheumatic conditions and as a diuretic [1].
European Union (EMA): Traditional herbal medicinal product status for both root (urinary complaints) and leaf (joint pain, urinary flushing) [1].
United States (FDA): Available as dietary supplement. No FDA-approved health claims [1].
WHO: Monograph available for Urtica dioica root and leaf with separate indications [1].
8 US supplement products
229
on-market products containing Stinging Nettle (NIH DSLD)
Brands carrying Stinging Nettle (125)
Click a brand to see its Stinging Nettle products.
9 Frequently paired with
10 Cite this page
Vancouver: Pkhakadze G. Stinging Nettle — safety profile [Internet]. Tbilisi: PHIG; 2026 [cited 2026 Aug 15]. Available from: https://supplement.ge/ingredients/stinging-nettle/
APA 7th: Pkhakadze, G. (2026). Stinging Nettle — Safety profile. Public Health Institute of Georgia. https://supplement.ge/ingredients/stinging-nettle/
📋 Editorial information
Author: Prof. G. Pkhakadze, MD, MPH, PhD
Institution: Public Health Institute of Georgia (PHIG)
Affiliation: David Tvildiani Medical University (DTMU)
First published: January 2026
Last reviewed: 2026-05-29
Next review: February 2027
References: 4 cited sources
COI: SupplementIndex receives no funding from supplement manufacturers. All content independently authored by PHIG.
Process: Systematic literature review
📄 License & reuse
Published under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt for any purpose with attribution.
Pkhakadze G. "Stinging Nettle — Safety Profile." SupplementIndex, PHIG, 2026. https://supplement.ge/ingredients/stinging-nettle/ CC BY 4.0.
GP
Prof. G. Pkhakadze, MD, MPH, PhD
Professor of Public Health · Head of Department, DTMU
Editor-in-Chief, Georgian Medical Journal (ISSN 3088-4322)
Chair, Public Health Institute of Georgia · UEMS Public Health Section
Educational and public health purposes. CC BY 4.0. Consult your healthcare provider before starting any supplement. Corrections: info@accreditation.ge. Publisher: PHIG