1. Summary of the characteristics of included studies.
| Study | Trial period | Country | n | Follow‐up | Brand and daily dosage (when available) | Co‐intervention | Age mean (SD) | IPSS mean (SD) | Prostate volume mean (SD) | |||
| I | C | I | C | I | C | |||||||
| Studies comparing Serenoa repens with placebo | ||||||||||||
| Argirović 2013 | 2008 to 2010 | Serbia | 199 | 6 months | Prostamol Uno 320 mg | Tamsulosin | 65.9 (7.4) | 56.8 (7.7) | 15.6 (3.2) | 16.2 (4.9) | 31.2 (4.2) | 38.6 (11.6) |
| BASTA 2010 | 2006 to 2008 | International | 1011 | 12 months | Permixon* 320 mg daily Prostamol Uno 320 mg |
None | 64.61 (7.69) 65.14 (7.67) |
64.14 (7.69) | N/A | N/A | N/A | N/A |
| Barry 2011 | 2008 to 2010 | USA | 369 | 72 weeks | Prosta Urgenin Uno 320 mg | None | 61.25 (8.72) | 60.7 (8.08) | 14.42 (4.29) | 14.69 (4.75) | N/A | N/A |
| Bauer 1999 | N/A | Germany/Italy | 101 | 6 months | Talso Uno 320 mg daily | None | 66.1 | 9.6 | 8.9 | 34.5 | 31.7 | |
| Bent 2006 | 2001 to 2004 | USA | 225 | 14 months | Carbon dioxide extract 320 mg | None | 62.9 (8.0) | 63.0 (7.4) | 15.7 (5.7) | 15.0 (5.3) | 34.7 (13.9) | 33.9 (15.2) |
| Boccafoschi 1983 | N/A | Italy | 22 | 60 days | Permixon* 320 mg | None | 68 (55 to 80) | 68 (54 to 78) | N/A | N/A | N/A | N/A |
| Champault 1984 | N/A | France | 110 | 30 days | Permixon* 320 mg | None | N/A | N/A | N/A | N/A | N/A | N/A |
| Descotes 1995 | 1995 | France | 176 | 30 days | Permixon* 320 mg | None | 65.6 (8.4) | 67 (7.6) | N/A | N/A | N/A | N/A |
| Gerber 2001 | 1999 to 2000 | USA | 85 | 6 months | SR 320 mg | None | 64.6 (± 9.9) | 65.3 (± 9.7) | 16.7 (± 4.9) | 15.8 (± 4.8) | N/A | N/A |
| Glémain 2002 | N/A | France | 329 | 52 weeks | Permixon* 320 mg | Tamsulosin | 65.2 (7.9) | 64.4 (7.7) | 16.2 (5.2) | 16.3 (5.6) | 40.8 (16.5) | 38.6 (15) |
| Hizli 2007 | 2005 | Turkey | 60 | 6 months | Permixon* 320 mg | Tamsulosin | 60.2 (6.3) | 58.9 (5.7) | 15.6 (3.2) | 16.2 (4.7) | 31.2 (4.2) | 38.6 (11.6) |
| Hong 2009 | N/A | Korea | 62 | 12 months | SR 320 mg | None | 52.0 | 53.1 | 18.3 | 15.4 | 26.1 | 23.2 |
| Mandressi 1983 | N/A | Italy | 60 | 1 month | Permixon* 320 mg | None | N/A | N/A | N/A | N/A | N/A | N/A |
| Reece Smith 1986 | N/A | UK | 70 | 12 weeks | Permixon* 320 mg | None | 66.15 (5.86) | 67.03 (6.03) | N/A | N/A | N/A | N/A |
| Ryu 2015 | 2012 to 2013 | Korea | 120 | 12 months | Permixon* 320 mg | Tamsulosin | 62.5 (1.21) | 63.4 (1.44) | 19.6 (0.73) | 20 (0.85) | 30.1 (0.93) | 30.2 (0.67) |
| Shi 2008 | N/A | China | 94 | 3 months | Prostataplex (dosing not reported) | None | 65.91 | 64.04 | 16.85 | 14.46 | 47.72 | 48.38 |
| Sudeep 2020 | N/A | India | 99 | 12 weeks | VISPO/SPO 400 mg | None | 57.76 (7.25) | 55.18 (8.56) | 20.00 (4.41) | 20.00 (3.74) | N/A | N/A |
| Willetts 2003 | 1999 to 2000 | Australia | 100 | 12 weeks | Carbon dioxide extract 320 mg | None | 62.1 (1.2) | 63.9 (1.3) | N/A | N/A | N/A | N/A |
| Ye 2019 | 2014 to 2016 | China | 354 | 24 weeks | SR 320 mg | None | 61.47 (5.20) | 60.32 (5.96) | 14.42 (3.88) | 14.34 (4.08) | 37.0 (19.7) | 37.3 (25.4) |
| Studies comparing phytotherapy containing Serenoa repens with placebo | ||||||||||||
| Carbin 1990 | 1990 | Sweden/Denmark | 55 | 3 months | Curbicin (PSO 480 mg + SR 480 mg) |
None | 62.0 (6.7) | 61.2 (5.8) | N/A | N/A | N/A | N/A |
| Coulson 2013 | N/A | Australia | 60 | 3 months | ProstateEZE Max (PSO 160 mg, epilobium 500 mg, lycopene 2.1 mg, pygeum 15 g + SR 660 mg) |
None | 63 (10.1) | 64.9 (9.6) | 19.5 | 18 | N/A | N/A |
| Iacono 2015 | N/A | Italy | 185 | 6 months | Tradamixina (Eisenia 80 mg, Tribulus 100 mg, chitosan oligosaccharide (Biovis) 100 mg + SR 320 mg) |
None | 64.2 (8.6) | 20.6 (5.4) | N/A | N/A | N/A | |
| Lopatkin 2005 | 1997 to 2000 | Russia | 257 | 24 weeks | PRO 160/120 (Sabal‐Urtica 240 mg + SR 320 mg) |
None | 67 (7) | 68 (6) | 17.4 (3.3) | 17.8 (3.3) | 43.5 (17.6) | 44.8 (17.6) |
| Marks 2000 | 1997 to 1998 | USA | 44 | 6 months | Nettle root 240 mg, PSO 480 mg, lemon 99 mg, vitamin A 570 IU + SR 318 mg | None | 65.1 (8.1) | 62.9 (9.3) | 18.1 (7.2) | 16.6 (5.3) | 58.5 (29.8) | 55.6 (26.7) |
| Metzker 1996 | N/A | Germany | 40 | 12 months | Prostagutt forte (Sabal‐Urtica 240 mg + SR 320 mg) |
None | 66.0 | 65.1 | 18.6 | 19.0 | N/A | N/A |
| Morgia 2014 | 2011 to 2012 | Italy | 225 | 12 months | Profluss (selenium and lycopene + SR 320 mg) |
Tamsulosin | 65 | 66 | 20 | 19 | 45 | 45 |
| Preuss 2001 | N/A | USA | 144 | 3 months | Cernitin AF (Cernitin 378 mg, vitamin E 100 IU + SR with beta‐sitosterol 286 mg) |
None | N/A | N/A | 18.9 | 17.1 | N/A | N/A |
(*) Hexanic extract of Serenoa repens; C: control; I: intervention; IPSS: International Prostate Symptom Score; IU: international units; N/A: not available (not described); PSO: pumpkin seed oil; SR: Serenoa repens;SD: standard deviation