Nettle for benign prostatic hyperplasia (BPH) - what do studies say

Benign prostatic hyperplasia (BPH) affects over 50% of men over 60 years old and over 80% over 80 years old (Lokeshwar et al., Asian Journal of Urology, 2019). Frequent trips to the bathroom, weak urine stream, feeling of incomplete bladder emptying - these are symptoms that many men do not want or cannot wait to see a urologist. Nettle root (Urtica dioica radix) is one of the most commonly used herbs for prostate ailments in Europe. We examine what clinical studies really say.

KEY INFORMATION
• RCT Safarinejad (2005, 620 men) showed a reduction in IPSS by 5.7 points vs 2.7 for placebo after 6 months (Safarinejad, Journal of Herbal Pharmacotherapy, 2005).
• The nettle root alleviates urological symptoms but does not reduce prostate volume - a different mechanism than finasteride.
• EMA classifies preparations containing Urtica dioica radix as traditional herbal use for BPH symptoms.
• Standardowa dawka w badaniach: 360 mg ekstraktu dziennie (120 mg × 3); efekty po 6-8 tygodniach.

What is BPH and why are men seeking herbal solutions?

BPH is a benign enlargement of the transitional zone of the prostate, which compresses the urethra with age and leads to lower urinary tract symptoms (LUTS). Standard treatment includes alpha-blockers (tamsulosin), 5-alpha-reductase inhibitors (finasteride, dutasteride), and - in advanced cases - surgical procedures. All these methods have side effects: alpha-blockers can lower blood pressure and cause ejaculation disorders, while finasteride can affect libido and erection in about 5-8% of men.

This drives many patients to seek herbal alternatives. In Germany, Austria, and Switzerland, preparations made from nettle root, saw palmetto, and rye pollen are commonly used and reimbursed in healthcare systems as supportive treatment for BPH. In Poland, their availability is increasing, although awareness regarding quality and scientific evidence remains uneven.

Key clinical study: Safarinejad 2005

The largest and most frequently cited study on nettle root in BPH is the randomized, double-blind trial by Safarinejad from Tehran, involving 620 men with mild to moderate BPH symptoms (IPSS 7-19). Patients received 360 mg of nettle root extract daily or placebo for 6 months. Results: IPSS score reduction of 5.7 points in the nettle group vs 2.7 for placebo; improvement in urinary flow Qmax of 8.2 ml/s vs 3.4 ml/s; reduction in post-void residual volume (Safarinejad, Journal of Herbal Pharmacotherapy, 2005). The differences were statistically significant.

We noticed that the Safarinejad study is often cited uncritically. It is worth noting its limitations: it was conducted in Iran and has not been repeated in Western European conditions with identical methodology. The extract "Bazoton uno" used in the study has a specific chemical profile - other nettle root preparations may differ in composition and concentration of active polyphenols. The results are promising, but they cannot be automatically extrapolated to all nettle supplements.

An earlier study by Schmidt and colleagues (1983, n=67) showed improvement in subjective symptom assessment in 86% of men using nettle extract for 3-6 months, but without a strict control group. The open study by Vonhold (1989, n=4480) - one of the largest observational studies - confirmed a reduction in nocturia (nighttime urination) and improvement in urine flow after 20-40 weeks (Vonhold, Urologe B, 1989).

How does nettle root affect the prostate?

Mechanism of action Urtica dioica radix is complex and multifaceted. Nettle root extract contains polysaccharides, lectins, plant sterols (including beta-sitosterol), and polyphenols that may act synergistically. In vitro studies and animal models indicate several possible mechanisms (Chrubasik et al., Phytomedicine, 2007):

• Inhibition of SHBG (sex hormone-binding globulin) binding to membrane receptors on prostate cells - reduces androgen-stimulated prostate cell proliferation.
• Inhibition of 5-alpha-reductase - the enzyme that converts testosterone to dihydrotestosterone (DHT), although the effect is weaker than that of finasteride.
• Inhibition of aromatase activity - an estrogen enzyme that may play a role in BPH.
• Anti-inflammatory action by inhibiting COX-2 and NF-κB

Does nettle root reduce prostate size?

This is a key question, and the answer is clear: no. The Safarinejad study measured prostate volume ultrasonographically and found no statistically significant difference between the nettle group and placebo after 6 months. The action of nettle root is to alleviate urological symptoms (LUTS), not to reduce the gland itself (Safarinejad, 2005).

This is an important clinical distinction. Finasteride and dutasteride reduce prostate volume by 20-30% after one year of use, which translates to a reduced risk of urinary retention and the need for surgery. Alpha-blockers and herbal preparations - including nettle - primarily act symptomatically, relaxing the smooth muscles of the urethra and reducing inflammation. For men with small or moderate prostates and bothersome symptoms, this is a sufficient approach. In cases of large glands and risk of complications, urological consultation is essential.

Nettle in combination with other herbs - what studies say.

The combination of nettle root with saw palmetto (Serenoa repens). A randomized study comparing the combined preparation of nettle + saw palmetto with finasteride over 48 weeks showed comparable efficacy of both therapies in reducing prostate volume and improving urine flow, with simultaneously fewer adverse effects in the herbal group (Sokeland & Albrecht, BJU Int, 2000). This is one of the stronger arguments for the herbal approach in mild to moderate BPH symptoms.

Our observations indicate that combined preparations (nettle + saw palmetto + rye pollen) are popular in Germany as a first-line treatment for mild BPH symptoms, recommended by some urologists before starting medications. In Poland, this practice is less common, which may be due to lower awareness among clinicians regarding prostate phytotherapy and the lack of reimbursement for herbal preparations.

Safety and adverse effects of nettle root

Nettle root (Urtica dioica radix) is among the better-tolerated herbal preparations used in urology. In the Safarinejad study, the profile of adverse effects was comparable to placebo: a few participants reported mild gastrointestinal discomfort (abdominal pain, nausea), which subsided after taking the preparation with food (Safarinejad, 2005). No cases of hepatotoxicity or significant hormonal disturbances were reported.

EMA in the monograph for Urtica dioica radix classifies the preparation as traditional herbal use and does not require special warnings regarding the liver or kidneys when using the recommended doses for up to 4-6 weeks. Longer use has not been formally assessed, but clinical practice in Germany suggests good tolerance with prolonged treatment (EMA Herbal Monograph, Urtica dioica radix).

Caution is advised for patients taking diuretics - nettle root exhibits weak diuretic effects and may enhance their effect. Interaction with anticoagulants (warfarin) is theoretically possible due to the vitamin K content in leaf preparations, but the root extract has a different profile and the risk is low. In case of doubts, it is always worth consulting a doctor or pharmacist.

Frequently Asked Questions

Does nettle really help with BPH?

Yes, with moderate strength of evidence. The largest RCT (Safarinejad, 2005, n=620) showed a statistically significant reduction in IPSS by 5.7 points vs 2.7 for placebo after 6 months (Safarinejad, Journal of Herbal Pharmacotherapy, 2005). The effect is real, but milder than that of alpha-blockers.

What dose of nettle root is used in studies?

In the Safarinejad study, 360 mg of nettle root extract was used daily (120 mg × 3 daily). EMA in the monograph for Urtica dioica The radix indicates 459 mg of dry extract as the traditionally used daily dose (EMA Herbal Monograph, Urtica dioica radix).

How long should nettle be used for prostate issues?

Clinical effects are observed after 6-8 weeks of regular use, with optimal action after 3-6 months. EMA classifies nettle root preparations in the category of traditional herbal use for BPH symptoms. If there is no improvement after 3 months, urological consultation is indicated.

Does nettle reduce the prostate?

No - available studies have not shown a significant reduction in prostate volume measured by ultrasound (Safarinejad, 2005). Its action is based on alleviating urological symptoms (IPSS). This distinguishes nettle from 5-alpha-reductase inhibitors (finasteride, dutasteride), which physically reduce the gland.

How does nettle root affect the prostate?

The multifaceted mechanism includes inhibiting the binding of SHBG to receptors on prostate cells, inhibiting aromatase and 5-alpha-reductase, and anti-inflammatory action through COX-2 inhibition (Chrubasik et al., Phytomedicine, 2007). None of these effects dominate - they likely work synergistically.

Can nettle for prostate be combined with urological medications?

The combination with saw palmetto has been clinically studied and showed effectiveness comparable to urological medications (Sokeland & Albrecht, BJU Int, 2000). Combining with alpha-blockers requires medical consultation - risk of additive blood pressure reduction. With 5-alpha-reductase inhibitors - consultation is mandatory.

This article is for informational and educational purposes and does not replace consultation with a doctor. If you are pregnant, breastfeeding, taking medications, or have chronic conditions, consult the use of supplements or herbs with a specialist.

Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04