Stinging Nettle and Testosterone: Clinical Evidence, Mechanisms, and What Utah Men Should Know

Stinging Nettle and Testosterone: Clinical Evidence, Mechanisms, and What Utah Men Should Know

Medical Disclaimer: This article provides educational information based on peer-reviewed research. It does not constitute medical advice. Consult with a qualified healthcare provider before starting any supplement regimen. Treatment decisions at Arsenal Men's Health are made by licensed providers based on individual clinical evaluation.

Introduction

If you've researched natural approaches to supporting testosterone levels, you've likely encountered stinging nettle (Urtica dioica). This perennial plant—found throughout North America, Europe, and Asia—has been used in traditional medicine for over 2,000 years. Today, it appears in countless "testosterone booster" supplements, often marketed with bold claims about its ability to enhance male hormonal health.

But what does the clinical evidence actually show? Can stinging nettle meaningfully impact testosterone levels in men? And more importantly, what should Utah men understand before investing in nettle supplements?

At Arsenal Men's Health, we believe in evidence-based medicine. Our approach combines peer-reviewed research with clinical expertise to provide honest, accurate information—even when that information challenges popular supplement marketing claims. This comprehensive guide examines the scientific evidence for stinging nettle's effects on testosterone, its proposed mechanisms of action, and when professional hormone optimization may be more appropriate.

What Is Stinging Nettle?

Stinging nettle (Urtica dioica L.) is a perennial flowering plant in the Urticaceae family. Its name derives from the fine, hair-like structures (trichomes) covering its leaves and stems that inject irritating chemicals—including formic acid, histamine, and acetylcholine—when touched, causing the characteristic "sting."

Different Plant Parts, Different Uses: It's crucial to understand that different parts of the stinging nettle plant contain different bioactive compounds and serve different therapeutic purposes:

• Nettle Root (Radix): Contains lignans, polysaccharides, and sterols. Used primarily for prostate health and hormonal applications. This is the part most relevant to testosterone discussions.

• Nettle Leaf (Folium): Rich in flavonoids, vitamins, and minerals. Traditionally used for allergies, arthritis, and anti-inflammatory purposes. Contains minimal lignans relevant to hormone modulation.

Key Point: When evaluating stinging nettle supplements for hormonal effects, always verify that the product contains root extract, not leaf extract. Many inexpensive supplements substitute cheaper leaf material, which lacks the lignans responsible for SHBG interactions.

Proposed Mechanisms: How Nettle Might Affect Testosterone

Stinging nettle root has been studied for several mechanisms that could theoretically influence testosterone availability. Understanding these mechanisms requires distinguishing between in vitro (test tube) findings and in vivo (living organism) evidence.

1. Sex Hormone-Binding Globulin (SHBG) Interaction

The most well-documented mechanism involves nettle root's interaction with SHBG. In healthy men, approximately 55-60% of circulating testosterone is bound to SHBG, rendering it biologically inactive. Only "free" testosterone—approximately 2-3% of total testosterone—is immediately available for tissue uptake and biological activity.

Nettle root contains several lignans, including:

• (+)-neoolivil

• (-)-secoisolariciresinol

• Dehydrodiconiferyl alcohol

• 3,4-Divanillyltetrahydrofuran (3,4-DVTHF) – the most potent SHBG-binding lignan

A seminal 1997 study by Schöttner et al. in Planta Medica demonstrated that these lignans bind to SHBG with varying affinities. The compound 3,4-divanillyltetrahydrofuran showed "outstandingly high" binding affinity. By occupying SHBG binding sites, these lignans could theoretically prevent SHBG from binding testosterone, thereby increasing free testosterone availability.

Additionally, Hryb et al. (1995) found that aqueous nettle root extract inhibited SHBG binding to its receptor on human prostatic membranes in a dose-dependent manner, with complete inhibition at concentrations of 10 mg/mL.

2. Aromatase Inhibition

Aromatase is the enzyme responsible for converting testosterone into estradiol (estrogen). Some research suggests nettle root may contain compounds that inhibit aromatase activity. A study by Gansser and Spiteller (1995) identified 9-oxo-10,12-octadecadienoic acid in nettle root as having moderate aromatase-inhibiting properties.

If nettle truly inhibits aromatase, this could theoretically:

• Reduce testosterone-to-estrogen conversion

• Maintain higher testosterone levels

• Lower circulating estrogen

However, comprehensive reviews including Chrubasik et al. (2007) in Phytomedicine concluded that while aromatase inhibition is theoretically possible, "the bioactivity would be minimal" at achievable doses in humans.

3. 5-Alpha Reductase Inhibition

5-alpha reductase converts testosterone to dihydrotestosterone (DHT), a more potent androgen involved in prostate growth and male pattern baldness. Some research suggests nettle root may inhibit this enzyme.

Nahata and Dixit (2012) in Andrologia investigated nettle's effects on testosterone-induced prostatic hyperplasia in rats and found evidence of 5-alpha reductase inhibitory activity. The active compounds β-sitosterol and scopoletin were isolated and characterized.

This mechanism relates more to prostate health than testosterone enhancement—by inhibiting DHT conversion, nettle may help preserve testosterone levels while reducing androgenic stimulation of the prostate.

Clinical Evidence: What Human Studies Actually Show

While the mechanisms described above are scientifically plausible, the critical question is: Do these effects translate to meaningful testosterone improvements in living humans?

The Safarinejad Study (2005)

The largest and most rigorous randomized controlled trial examining nettle for BPH was conducted by Safarinejad (2005), published in the Journal of Herbal Pharmacotherapy:

• Design: 6-month, double-blind, placebo-controlled, randomized, crossover trial

• Participants: 620 men with BPH; 558 completed (90% completion rate)

• Intervention: 120 mg aqueous nettle root extract three times daily

• Follow-up: Extended to 18 months total

Results:

• 81% of nettle group reported improved urinary symptoms vs. 16% placebo (P < 0.001)

• International Prostate Symptom Score (IPSS) decreased from 19.8 to 11.8 (P = 0.002)

• Peak urinary flow improved by 8.2 mL/s vs. 3.4 mL/s placebo (P < 0.05)

• Prostate volume decreased from 40.1 cc to 36.3 cc (P < 0.001)

Critical Finding: "Serum PSA and testosterone levels were unchanged in both groups." Despite significant improvements in BPH symptoms, this well-designed trial found no effect on circulating testosterone levels.

Systematic Reviews and Meta-Analyses

A 2024 systematic review published in ScienceDirect evaluated six RCTs with 1,210 BPH patients:

• Meta-analysis showed nettle improved IPSS scores (SMD -2.06, 95% CI [-3.22, -0.91])

• Reduced PSA levels (MD -0.37 ng/mL, 95% CI [-0.50, -0.23])

• No quality of life improvement (SMD -0.59, 95% CI [-1.57, 0.38])

• Evidence rated as "very low" to "low" certainty

Men et al. (2016) in the African Journal of Traditional, Complementary and Alternative Medicines conducted a meta-analysis of 5 RCTs with 1,128 patients and found statistically significant improvements in IPSS, peak urinary flow, and prostate volume—but notably, none of these studies demonstrated testosterone increases.

The 2021 Systematic Review on Herbs and Testosterone

A comprehensive 2021 systematic review by Smith et al. in Advances in Nutrition examined randomized controlled trials on herbal effects on testosterone in men. Of 32 studies covering 13 different herbs, the review found:

• Only 9 of 32 studies (28%) showed statistically significant testosterone increases

• Herbs with positive evidence: Fenugreek seed extract and ashwagandha root extract

• Stinging nettle was not among the herbs with demonstrated testosterone-boosting effects

The authors concluded that "conclusions are moderated by the paucity of research for many herbs, the variation in dosages and extracts used, small sample sizes, and the heterogeneity of study characteristics."

The Free Testosterone Question

Proponents of nettle often argue that even if total testosterone doesn't increase, binding to SHBG could increase free testosterone—the biologically active fraction. This argument merits examination.

The Fischer and Wilbert (1992) study cited in Chrubasik's comprehensive review found that 7 months of nettle root extract (BAZ 1200 mg/day) produced:

• 10% increase in testosterone concentrations

• 10% increase in 5α-DHT

• 10% increase in estradiol

• Decrease in SHBG levels

However, Vontobel et al. (1985) found no difference for testosterone, androstandiol, or acid phosphatase between nettle and placebo groups. The inconsistency between these studies highlights the uncertain nature of the evidence.

A 2020 crystallographic study published in the Journal of Biological Chemistry confirmed that 3,4-divanillyltetrahydrofuran from nettle does bind to SHBG—but with "relatively low affinity" compared to synthetic compounds. The study found DVT "slightly" increased testosterone bioavailability in cell cultures, but the clinical significance remains unestablished.

Prostate Health: Where the Evidence Is Actually Stronger

While stinging nettle's effects on testosterone remain unproven, the evidence for its benefits in benign prostatic hyperplasia (BPH) is more substantial. This is important context because many men over 50 dealing with low testosterone also experience BPH symptoms.

The German Commission E and European Scientific Cooperative on Phytotherapy (ESCOP) both recommend nettle root for the symptomatic treatment of urinary disorders associated with BPH stages I-II. This recommendation is based on:

• Over 40,000 men treated in 34 clinical studies

• Consistent improvements in urinary flow and symptoms

• Good safety profile with minimal adverse effects

• Synergistic effects when combined with saw palmetto

Lopatkin et al. (2005) demonstrated that a combination of saw palmetto (160 mg) and nettle root (120 mg) extract improved urinary symptoms over 96 weeks with maintained efficacy and excellent tolerability.

Dosage, Forms, and Safety Considerations

Evidence-Based Dosing

Based on clinical trials, typical dosages for nettle root extract include:

• BPH Studies: 300-600 mg daily of standardized root extract

• SHBG Modulation: 450-1,200 mg daily (based on limited studies)

• Traditional Use: 4-6 g dried root as infusion

Duration: Most BPH studies show improvements in 8-12 weeks. Hormone support effects, if any, may take 4-6 weeks.

Safety Profile

Stinging nettle root is generally well-tolerated. In clinical trials, adverse events were minimal and comparable to placebo. Reported side effects include:

• Mild gastrointestinal upset (uncommon)

• Sweating

• Allergic reactions (rare)

• Diuretic effects

Drug Interactions and Contraindications

Important Precautions:

• Blood Thinners: Nettle contains vitamin K and may reduce anticoagulant efficacy

• Diabetes Medications: May lower blood sugar; monitor glucose closely

• Blood Pressure Medications: Additive hypotensive effects possible

• Lithium: Diuretic effects may increase lithium levels

• Sedatives: May enhance drowsiness

• Pregnancy: Contraindicated due to potential uterine contractions

When Supplements Aren't Enough: Understanding Clinical Hypogonadism

Here's the honest clinical perspective: Even if stinging nettle could marginally increase free testosterone through SHBG modulation, this mechanism is unlikely to address clinical testosterone deficiency.

Men with symptomatic hypogonadism—characterized by total testosterone below 300 ng/dL with symptoms like:

• Persistent fatigue

• Reduced libido

• Erectile dysfunction

• Decreased muscle mass

• Mood changes and cognitive fog

• Increased body fat

—require medical evaluation and potentially clinician-supervised hormone optimization therapy (TRT). The FDA has approved testosterone replacement therapy for men whose low testosterone is associated with specific medical conditions affecting testosterone production.

Supplements like stinging nettle should not delay appropriate medical care for clinically significant hormone deficiency.

Practical Recommendations for Utah Men

When Stinging Nettle May Be Appropriate

• Men with mild BPH symptoms seeking natural support

• As adjunct therapy alongside medical treatment (with provider approval)

• Men with normal testosterone seeking general prostate health support

• Those interested in traditional herbal approaches with realistic expectations

When to Seek Medical Evaluation Instead

• Symptoms of low testosterone (fatigue, low libido, erectile dysfunction)

• Total testosterone below 300 ng/dL

• Age-related testosterone decline affecting quality of life

• Significant BPH symptoms requiring medical management

• Any urinary symptoms requiring evaluation to rule out serious conditions

If You Choose to Try Nettle Root

• Select root extract (not leaf)

• Look for standardized products with verified lignan content

• Start with 300-450 mg daily

• Allow 8-12 weeks for assessment

• Monitor for drug interactions

• Consider lab work before and after to objectively assess any effects

The Bottom Line

Stinging nettle root contains bioactive compounds that demonstrably interact with SHBG in laboratory settings. However, the clinical evidence does not support using nettle supplements to increase testosterone levels in men.

The most well-designed human trials consistently show:

• No significant change in serum testosterone

• Meaningful improvements in BPH symptoms

• Good safety with minimal side effects

At Arsenal Men's Health, we believe Utah men deserve honest, evidence-based information—not marketing hype. While stinging nettle may offer benefits for prostate health and urinary symptoms, it should not be considered a testosterone booster based on current evidence.

If you're experiencing symptoms of low testosterone, the most effective approach is comprehensive laboratory evaluation followed by clinician-supervised treatment when appropriate. Our providers offer personalized hormone optimization protocols backed by peer-reviewed research and Endocrine Society guidelines.

Ready to Get Answers?

Book your free consultation with Arsenal Men's Health.Comprehensive lab work. Expert evaluation. Evidence-based treatment.(385) 666-6292info@arsenalmenshealth.com

References

1. Schöttner M, Gansser D, Spiteller G. Lignans from the roots of Urtica dioica and their metabolites bind to human sex hormone binding globulin (SHBG). Planta Med. 1997;63(6):529-532.

2. Hryb DJ, Khan MS, Romas NA, Rosner W. The effect of extracts of the roots of the stinging nettle (Urtica dioica) on the interaction of SHBG with its receptor on human prostatic membranes. Planta Med. 1995;61(1):31-32.

3. Safarinejad MR. Urtica dioica for treatment of benign prostatic hyperplasia: a prospective, randomized, double-blind, placebo-controlled, crossover study. J Herb Pharmacother. 2005;5(4):1-11.

4. Chrubasik JE, Roufogalis BD, Wagner H, Chrubasik S. A comprehensive review on the stinging nettle effect and efficacy profiles. Part II: Urticae radix. Phytomedicine. 2007;14(7-8):568-579.

5. Nahata A, Dixit VK. Ameliorative effects of stinging nettle (Urtica dioica) on testosterone-induced prostatic hyperplasia in rats. Andrologia. 2012;44 Suppl 1:396-409.

6. Gansser D, Spiteller G. Aromatase inhibitors from Urtica dioica roots. Planta Med. 1995;61(2):138-140.

7. Lopatkin N, Sivkov A, Walther C, et al. Long-term efficacy and safety of a combination of sabal and urtica extract for lower urinary tract symptoms--a placebo-controlled, double-blind, multicenter trial. World J Urol. 2005;23(2):139-146.

8. Men Z, Zhang K, Xia X, et al. The efficacy and safety of Urtica dioica in treating benign prostatic hyperplasia: A systematic review and meta-analysis. Afr J Tradit Complement Altern Med. 2016;13(2):143-150.

9. Smith SJ, Lopresti AL, Teo SYM, Fairchild TJ. Examining the effects of herbs on testosterone concentrations in men: A systematic review. Adv Nutr. 2021;12(3):744-765.

10. Round P, Das S, Wu TS, Wähälä K, Van Petegem F, Hammond GL. Molecular interactions between sex hormone-binding globulin and nonsteroidal ligands that enhance androgen activity. J Biol Chem. 2020;295(5):1202-1211.

11. Clemesha CG, Thaker H, Samplaski MK. 'Testosterone boosting' supplements composition and claims are not supported by the academic literature. World J Mens Health. 2020;38(1):115-122.

12. Bhusal KK, Magar SK, Thapa R, et al. Nutritional and pharmacological importance of stinging nettle (Urtica dioica L.): A review. Heliyon. 2022;8(6):e09717.

13. Moradi HR, Erfani Majd N, Esmaeilzadeh S, Fatemi Tabatabaei SR. The histological and histometrical effects of Urtica dioica extract on rat's prostate hyperplasia. Vet Res Forum. 2015;6(1):23-29.

14. Konrad L, Müller HH, Lenz C, Laubinger H, Aumüller G, Lichius JJ. Antiproliferative effect on human prostate cancer cells by a stinging nettle root (Urtica dioica) extract. Planta Med. 2000;66(1):44-47.

About Arsenal Men's Health

Arsenal Men's Health is a premium telehealth clinic serving Utah men. Our board-certified provider, Courtney LaSumner Bass, NP—a military veteran with specialized training in men's health and hormone optimization—delivers personalized, evidence-based care. We specialize in testosterone replacement therapy, sexual health, medical weight management, mental health, and men's wellness.

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