Herbal formula
Saw Palmetto and Nettle Root
Also known as PRO 160/120, WS 1541, Prostagutt duo, Prostagutt forte, Prostagut Forte, sabal and urtica extract, saw palmetto–nettle root combination
A German capsule of saw palmetto fruit and nettle root extracts, tested by its maker for urinary symptoms of an enlarged prostate.
Main use: Urinary symptoms of enlarged prostate
Promising clinical evidence
2 ingredients
Updated October 10, 2026
Key points
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01
One fixed pair of extracts
Each capsule holds 160 mg saw palmetto fruit extract and 120 mg nettle root extract, taken twice daily. The trial results apply to this product, not other blends.
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02
Beat placebo in maker-linked trials
In a 24-week trial of 257 Russian men, symptom scores fell 6 points versus 4 with placebo. Two authors worked for the manufacturer, Schwabe.
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03
Matched finasteride and tamsulosin
Trials in 516 and 140 men found symptom relief similar to two prescription drugs, but without placebo groups they cannot show that either treatment worked.
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04
Guidelines do not recommend it
US urologists judge positive recommendations for such supplements unwarranted. European guidelines weakly endorse only a different, hexane-extracted saw palmetto product.
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05
Get urinary symptoms checked first
It may ease symptoms but does not shrink the prostate. Blood in the urine, being unable to pass urine, or fever need a doctor promptly.
Saw palmetto and nettle root is best known as PRO 160/120, a soft capsule made by the German company Dr. Willmar Schwabe that combines two plant extracts used for the urinary symptoms of benign prostatic hyperplasia (BPH), the non-cancerous enlargement of the prostate that becomes common with age. Each capsule contains 160 mg of a saw palmetto fruit extract and 120 mg of a stinging nettle root extract. In Germany it was sold for years as Prostagutt forte and is now called Prostagutt duo; Schwabe says only the name changed, not the ingredients or the dose. Research papers call it PRO 160/120 or WS 1541, and Russian studies call it Prostagut Forte. Many supplements pair saw palmetto with nettle root, but the trials on this page tested this specific pair of extracts, made in a specific way, and their results belong to it alone.
Each herb had a medical career before the two were combined. Saw palmetto berries come from a low palm of the southeastern United States; according to the European Medicines Agency (EMA), Native Americans used them for infertility and impotence, and reports of their use for urinary complaints appear in the medical literature from the early twentieth century. EMA dates the first use of nettle root for urinary disorders to the 1950s, and Germany’s Commission E approved it for urination problems in early benign prostate enlargement in 1986. EMA’s 2025 assessment report on nettle root lists a combination with exactly these two extracts as authorized in Germany since 1976. The controlled trials came later: a small German placebo-controlled study published in 1996, a year-long comparison with finasteride reported in 1997, a Russian placebo-controlled trial in 2005, and a comparison with tamsulosin in 2006. Schwabe staff co-authored several of these papers, and the company funded a 2019 review that gathered them.
How the combination might work is not settled. Laboratory studies cited in the 2019 review suggest that saw palmetto extract inhibits 5-alpha-reductase, the enzyme that converts testosterone to the stronger androgen dihydrotestosterone, and blocks alpha-1 and muscarinic receptors in the lower urinary tract, while nettle root extract has shown anti-inflammatory and anti-proliferative effects. In a 2019 mouse study the combined extract reduced prostate weight and inflammation, but in a 2024 rat study it did not reduce prostate size. EMA states that the mechanism of saw palmetto is not known, and in people the combination barely changed prostate volume. This page covers what is in the capsule, the trials of the combination and who ran them, how they square with the large trials of saw palmetto alone, how it is taken, and when urinary symptoms need a doctor instead. Nothing here is medical advice.
See also
Herbs for Urinary Tract Health02 The blend
What’s in it
Ingredients in label order. Results from trials of this formula belong to the combination, not to any single herb in it.
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Saw palmetto · Fruit (soft extract)
160 mg per capsule
Serenoa repens
Soft extract (10–14.3:1) made with 90% ethanol, the kind EMA accepts as a traditional remedy at 320 mg a day. Large independent trials of saw palmetto alone found little or no benefit.
Read the saw palmetto monograph →
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Nettle root · Root (dry extract)
120 mg per capsule
Urtica dioica
Dry extract (7.6–12.5:1) made with 60% ethanol. The formula uses the root, not the leaf. EMA accepts nettle root only as a traditional remedy for prostate symptoms.
Read the stinging nettle monograph →
03 Evidence
What the research shows
Our rating for urinary symptoms of enlarged prostate, based on trials of this combination.
Two placebo-controlled trials have tested this capsule, both at one capsule twice daily. In the first, a single-center German study of 40 men by Metzker and colleagues (Urologe B 1996, summarized in the 2019 review), scores on the 35-point International Prostate Symptom Score (IPSS) fell from 18.6 to 11.1 over 24 weeks with the combination and from 19.0 to 17.6 with placebo. The larger trial, by Lopatkin and colleagues (World Journal of Urology 2005), randomized 257 men at Moscow centers after a two-week placebo run-in. After 24 weeks of double-blind treatment, IPSS fell by 6 points with the combination and 4 with placebo, and tolerability was similar. Peak urine flow, however, improved about equally in both groups. Two of the authors worked in Schwabe’s clinical research department. The 2-point advantage over placebo is smaller than the 3-point change that Schwabe’s own review cites as meaningful to patients.
After the blinded phase, every man in the Russian trial took the combination. In the open extension (Lopatkin, International Urology and Nephrology 2007), 219 men were followed to week 96: scores fell by 53% from baseline, urine flow rose by 19%, and urine left in the bladder fell by 44%, with one adverse event per 1,181 treatment days. Without a control group, these figures cannot separate a drug effect from placebo response or the natural ups and downs of symptoms. The largest trial compared the capsule with finasteride 5 mg, a prescription drug that shrinks the prostate. Sökeland and Albrecht (Urologe A 1997) enrolled 543 men with early BPH from 81 practices; after a placebo run-in, 516 were randomized to 48 weeks of double-blind treatment. Peak flow, the main outcome, rose by 1.9 ml/s with the combination and 2.4 ml/s with finasteride, within the preset equivalence margin, and IPSS fell from 11.3 to 6.5 versus 11.8 to 6.2. Finasteride shrank the prostate from 44.0 to 37.2 ml, while the combination barely changed it (42.7 to 42.4 ml).
In the finasteride trial, the combination caused fewer complaints of reduced ejaculate volume, erectile dysfunction, and headache, and a reanalysis of 431 of the men (Sökeland, BJU International 2000) found that results did not depend on prostate size. Engelmann and colleagues (Arzneimittel-Forschung 2006) then compared the capsule with tamsulosin 0.4 mg, an alpha-blocker, in 140 men with moderate to severe symptoms for 60 weeks. Median IPSS fell by 9 points in both groups, 32.4% versus 27.9% of men ended with mild symptoms, and the combination passed the trial’s test for being no worse than tamsulosin; Schwabe clinical research staff were among the authors. Comparison trials like these share a weakness: without a placebo arm, they cannot show that either treatment beat placebo, and men with BPH often improve on placebo. A 2019 narrative review by Kirschner-Hermanns and colleagues (Therapeutic Advances in Urology) called the combination a valid alternative to both drugs, but Schwabe funded it, one author was a Schwabe employee, and the company supplied unpublished trial results. We found no placebo-controlled trial of the product run independently of the manufacturer.
The large independent trials of saw palmetto alone point the other way. In the STEP trial (Bent, New England Journal of Medicine 2006), 225 men took 160 mg of saw palmetto extract twice daily or placebo for a year, with no difference in symptoms, urine flow, or PSA. In the CAMUS trial (Barry, JAMA 2011), 369 men took up to 960 mg a day for 72 weeks, and symptom scores fell by 2.20 points with saw palmetto and 2.99 with placebo. Franco and colleagues’ 2023 Cochrane review of 27 trials with 4,656 men concluded with high certainty that saw palmetto alone gives little to no benefit. Its eight trials of saw palmetto combined with other plant extracts, including the Russian PRO 160/120 trial, gave a murkier picture: pooling four of them (460 men) showed a 2.41-point advantage over placebo, which the reviewers rated low-certainty evidence that such combinations may make little to no difference. Neither result transfers neatly. The single-herb trials tested other saw palmetto products without nettle, and only a small open-label Russian study (Urologiia 2019, 102 men) has compared the combination with saw palmetto alone, so nettle’s contribution is unknown.
Regulators treat the herbs and the product separately. EMA has no monograph on the combination. For saw palmetto alone, its Committee on Herbal Medicinal Products grants well-established use only to a hexane extract; ethanol extracts like the one in this capsule (10–14.3:1, 90% ethanol) are accepted at 320 mg a day as traditional medicines, for use after a doctor has excluded serious conditions. Nettle root is accepted only as a traditional remedy, because in its 2025 review EMA judged its effectiveness not proven well enough for well-established use. In Germany, however, the combination holds a national marketing authorization, which EMA lists as based on well-established use since 1976, and it is sold without prescription in pharmacies. In the United States it is not an approved drug, and herbal supplements do not need approval from the Food and Drug Administration (FDA) before sale. The American Urological Association’s 2021 guideline says results for supplements containing saw palmetto, stinging nettle, and similar ingredients are too variable to warrant positive recommendations, and the European Association of Urology’s 2026 guideline weakly recommends only hexane-extracted saw palmetto, warning that one brand’s results cannot be extrapolated to others.
04 In practice
How it is taken
In Germany the tested product is sold as Prostagutt duo 160 mg/120 mg soft capsules, a non-prescription medicine available only in pharmacies, in packs of 60, 120, and 200; Schwabe also sells Prostagutt uno, which contains saw palmetto extract alone. The package leaflet (April 2023) lists 160 mg of soft extract of saw palmetto fruit (10–14.3:1, extracted with 90% ethanol) and 120 mg of dry extract of nettle root (7.6–12.5:1, extracted with 60% ethanol) per capsule, with hydrogenated soybean oil, glycerol, and gelatin polysuccinate among the other ingredients. The same combination has been sold in Russia as Prostagut Forte. Other saw palmetto and nettle root supplements use different extracts, amounts, and added ingredients, and the trials described here do not apply to them.
The leaflet dose for adult men is one capsule twice daily, morning and evening, swallowed whole with a little liquid, giving 320 mg of saw palmetto extract and 240 mg of nettle root extract a day. That is the dose used in every trial. The leaflet sets no time limit on use. Trials judged the effect at 24 weeks and followed men for up to 60 weeks, or 96 weeks in the open extension, so a fair trial means weeks to months, not days. For comparison, EMA’s single-herb monographs give 320 mg a day for ethanol extracts of saw palmetto, and 500 mg a day for the closest nettle root preparation (a 60% ethanol extract), so the nettle dose in this capsule is lower than EMA’s dose for nettle root used alone.
Get a diagnosis before starting, because the leaflet itself says the medicine only improves symptoms of an enlarged prostate without treating the enlargement, and advises seeing a doctor at regular intervals. A doctor can check for prostate cancer, infection, and bladder problems, and discuss treatments with stronger evidence. Stop and see a doctor if side effects appear, if symptoms worsen, or if fever, spasms, blood in the urine, painful urination, or difficulty passing urine develop, as EMA advises for both herbs. If you choose a product, a licensed herbal medicine states the plant part, extract ratio, solvent, and amount; a supplement labeled only “saw palmetto and nettle” may contain leaf instead of root, or extracts that have never been tested.
05 Caution
Before you use Saw Palmetto and Nettle Root
The combination was well tolerated in its trials. In the Russian placebo-controlled trial, tolerability was comparable to placebo, and in the finasteride trial the combination caused fewer adverse events, especially less reduced ejaculate volume, erectile dysfunction, and headache. The package leaflet lists occasional mild digestive complaints and rare allergic reactions such as itching, rash, and hives, and notes that the soybean oil in the capsule can very rarely cause allergic reactions. For each herb alone, EMA lists nausea, vomiting, diarrhea, and abdominal pain with ethanol saw palmetto extracts, especially on an empty stomach, and nausea, heartburn, fullness, flatulence, diarrhea, and allergic skin reactions with nettle root. Taking too much can intensify digestive upset and itching, according to the leaflet, which advises stopping and seeing a doctor if side effects occur.
The product is for adult men only. The leaflet says it must not be taken by anyone allergic to saw palmetto, nettle root, soy, or peanut, and that it is not intended for children and adolescents under 18. EMA sees no relevant use of either herb in women or children, and the National Center for Complementary and Integrative Health (NCCIH) says saw palmetto may be unsafe during pregnancy or breastfeeding. People with bleeding disorders, and anyone scheduled for surgery, should discuss it with their doctor or surgeon first. It is not a treatment for prostate cancer, prostatitis, or a urinary infection, and men already taking prescription BPH medicines should not swap them for it without medical advice.
Schwabe’s leaflet states that no interactions with other medicines are known for the combination, and EMA reports no interactions for nettle root. Saw palmetto is the ingredient to watch. EMA’s monograph notes a few suspected interactions with warfarin with raised INR values, and EMA’s assessment report notes that some saw palmetto product information warns of increased bleeding risk with phenprocoumon, warfarin, clopidogrel, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs). The same report describes a 53-year-old man taking saw palmetto who lost about 2 liters of blood during brain surgery. Anyone taking an anticoagulant or antiplatelet drug should talk to their prescriber before starting and expect closer monitoring. The trials compared the capsule with finasteride and tamsulosin rather than adding it to them, so there is little information on combining it with prescription prostate drugs.
This is a remedy for symptoms, not a substitute for a prostate check. Urinary symptoms in older men usually come from benign enlargement, but similar symptoms can come from prostate cancer, infection, or bladder problems, which is why the leaflet and EMA both send men to a doctor, and why EMA’s traditional-use indications apply only after a doctor has excluded serious conditions. Suddenly being unable to pass urine is an emergency. The leaflet singles out blood in the urine and acute urinary retention as reasons to see a doctor, and EMA adds fever, spasms, and painful urination, as well as symptoms that keep getting worse. Saw palmetto alone did not change PSA results in the STEP trial, but we did not find PSA results for the combination in the trial reports we reviewed, so tell your doctor you take it before a PSA test. Nothing here replaces a doctor’s assessment.
06 Questions
Frequently Asked Questions
It might help modestly, but the evidence comes almost entirely from the manufacturer. In a 24-week Russian trial of 257 men, symptom scores fell by 6 points with PRO 160/120 and 4 with placebo, and Schwabe staff co-authored the paper. Large independent trials of saw palmetto alone found little to no benefit, EMA accepts nettle root only as a traditional remedy, and Cochrane rated the evidence for saw palmetto combinations as low certainty.
No. The trials tested two specific extracts: saw palmetto fruit extracted with 90% ethanol and nettle root extracted with 60% ethanol, at 160 mg and 120 mg per capsule. Other products use different extracts, amounts, and added ingredients, and some contain nettle leaf instead of root. European urology guidelines warn that one brand’s results cannot be assumed for another.
In two manufacturer-linked trials, symptom relief was similar: IPSS fell from 11.3 to 6.5 with the combination and from 11.8 to 6.2 with finasteride over 48 weeks, and by 9 points with both the combination and tamsulosin over 60 weeks. It caused fewer sexual side effects than finasteride but did not shrink the prostate. Without placebo groups, these trials cannot show that either treatment beat placebo.
The trials measured the main effect after 24 weeks, so it is worth allowing a few months before judging it. The package leaflet sets no time limit on use, and men in the trials took it for up to 96 weeks. See your doctor at regular intervals, as the leaflet advises, and sooner if symptoms worsen.
It does not prevent or treat prostate cancer. Saw palmetto alone did not change PSA in the large STEP trial, but we did not find PSA results for this combination in its trial reports, so tell your doctor you take it before any PSA test. Urinary symptoms should be checked by a doctor before you start, because they can occasionally signal cancer.
Use caution. Schwabe lists no known interactions for the combination, but EMA notes a few suspected warfarin interactions with saw palmetto, and some saw palmetto product labels warn of extra bleeding risk with anticoagulants, clopidogrel, aspirin, and NSAIDs. Talk to your prescriber first, and tell your surgeon before any operation. Nettle root has no reported interactions.
No. The product is meant only for adult men, and the leaflet says it is not intended for anyone under 18. EMA sees no relevant use of saw palmetto or nettle root in women or children, and NCCIH says saw palmetto may be unsafe in pregnancy or breastfeeding. People allergic to soy or peanut should also avoid it, because the capsule contains soybean oil.
Several are used, but none has strong independent support. Pumpkin seed and pygeum are accepted in the EU as traditional remedies, and EMA grants well-established use only to a hexane extract of saw palmetto. Prescription alpha-blockers and 5-alpha-reductase inhibitors have much stronger evidence, so discuss the options with a doctor.
07 References
Sources
These references support the claims on this page. They are not an endorsement of any product. Each ingredient’s monograph carries its own full source list.
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Prostagutt duo 160 mg / 120 mg: Gebrauchsinformation (package leaflet)
Dr. Willmar Schwabe GmbH & Co. KG, 2023
Current German leaflet (April 2023): 160 mg saw palmetto soft extract (10–14.3:1, ethanol 90%) and 120 mg nettle root dry extract (7.6–12.5:1, ethanol 60%) per capsule; one capsule twice daily; soy and peanut contraindication; side effects; no known interactions; under-18s excluded.
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Prostagutt forte heißt jetzt Prostagutt duo
Dr. Willmar Schwabe GmbH & Co. KG, 2026
Manufacturer page stating that Prostagutt forte 160/120 mg was renamed Prostagutt duo with unchanged ingredients, indication, and dose; also lists Prostagutt uno (saw palmetto alone).
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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 Journal of Urology (PubMed 15928959), 2005
Lopatkin et al.: 257 men, 24 weeks double-blind; IPSS fell 6 vs 4 points with placebo; tolerability similar to placebo. Two authors from Schwabe’s clinical research department.
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Efficacy and safety of a combination of Sabal and Urtica extract in lower urinary tract symptoms: long-term follow-up of a placebo-controlled, double-blind, multicenter trial
International Urology and Nephrology (PubMed 18038253), 2007
Open extension: 219 men to week 96, all on the combination; IPSS down 53%, flow up 19%, residual urine down 44%; one adverse event per 1,181 treatment days. No control group.
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Combination of Sabal and Urtica extract vs. finasteride in benign prostatic hyperplasia (Alken stages I to II): comparison of therapeutic effectiveness in a one year double-blind study
Der Urologe A (PubMed 9340898), 1997
Sökeland and Albrecht: 543 men, 48 weeks, double-dummy versus finasteride; peak flow +1.9 vs +2.4 ml/s; IPSS 11.3 to 6.5 vs 11.8 to 6.2; fewer sexual side effects and headaches with the combination.
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Combined sabal and urtica extract compared with finasteride in men with benign prostatic hyperplasia: analysis of prostate volume and therapeutic outcome
BJU International (PubMed 10971268), 2000
Sökeland: subgroup analysis of 431 men from the finasteride trial (516 in the safety analysis); efficacy equivalent and unrelated to prostate size; fewer adverse events with the combination.
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Efficacy and safety of a combination of sabal and urtica extract in lower urinary tract symptoms: a randomized, double-blind study versus tamsulosin
Arzneimittel-Forschung (PubMed 16618015), 2006
Engelmann et al.: 140 men, 60 weeks; median IPSS fell 9 points in both groups; responders 32.4% vs 27.9%; non-inferiority shown. Co-authored by Schwabe clinical research staff.
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WS PRO 160 I 120 mg (a combination of sabal and urtica extract) in patients with LUTS related to BPH
Therapeutic Advances in Urology (PubMed 31656534), 2019
Kirschner-Hermanns et al.: narrative review of the four controlled trials, including the 40-man Metzker trial; extract specifications; funded by Schwabe, with a Schwabe employee as author and unpublished company data.
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Serenoa repens for the treatment of lower urinary tract symptoms due to benign prostatic enlargement
Cochrane Database of Systematic Reviews (PubMed 37345871), 2023
Franco et al.: 27 trials, 4,656 men; saw palmetto alone gives little to no benefit (high certainty); combinations with other plant extracts, including PRO 160/120, may make little to no difference (low certainty).
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Saw palmetto for benign prostatic hyperplasia
New England Journal of Medicine (PubMed 16467543), 2006
Bent et al. (STEP): 225 men, 160 mg saw palmetto twice daily for a year; no difference from placebo in symptoms, flow, prostate size, or PSA.
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Effect of increasing doses of saw palmetto extract on lower urinary tract symptoms: a randomized trial
JAMA (PubMed 21954478), 2011
Barry et al. (CAMUS): 369 men, up to 960 mg daily for 72 weeks; symptom scores fell 2.20 points vs 2.99 with placebo; no benefit on any outcome.
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European Union herbal monograph on Serenoa repens (W. Bartram) Small, fructus
European Medicines Agency (EMA/HMPC/280079/2013), 2015
Well-established use for a hexane extract only; traditional use for ethanol extracts (7.5–14.3:1, 90–96% ethanol) at 320 mg daily; warfarin INR warning; side effects; no relevant use in women or children.
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Assessment report on Urtica dioica L.; Urtica urens L., radix (Revision 1)
European Medicines Agency (EMA/HMPC/322627/2023), 2025
Nettle root efficacy not proven for well-established use, so traditional use only; lists the saw palmetto and nettle root combination as authorized in Germany since 1976; history of nettle root use.
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Saw palmetto
National Center for Complementary and Integrative Health (NIH), 2025
Consumer summary (April 2025): saw palmetto probably not helpful for BPH symptoms; combinations uncertain; PSA unaffected; may be unsafe in pregnancy or breastfeeding; supplements not FDA-approved before sale.
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Management of lower urinary tract symptoms attributed to benign prostatic hyperplasia: AUA guideline part I, initial work-up and medical management
Journal of Urology (PubMed 34384237), 2021
American Urological Association: results for supplements containing saw palmetto, stinging nettle, and similar ingredients are variable, so positive recommendations are not warranted.
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EAU Guidelines on the Management of Non-neurogenic Male LUTS: plant extracts, phytotherapy
European Association of Urology, 2026
Weak recommendation for hexane-extracted saw palmetto only; effects of one brand cannot be extrapolated to others; no recommendation for other plant extracts or combinations.