Table 2. Patient and study characteristics in double-blind, randomized placebo-controlled trials of antioxidant supplementation for erectile dysfunction.
| Study | Design | Numbera | Mean age (range), y | IIEFc | Daily dosage | Duration |
|---|---|---|---|---|---|---|
| Agostini et al (2006) [21] | Parallel | 88/88 | 60 (50–70)b | 15.6 | Myoinositol (4 g); folic acid (0.4 mg) | 12 weeks |
| Cavallini et al (2004) [22] | Parallel | 45/45 | 65 (60–74) | 8.0 | Propionyl-L-carnitine (2 g); acetyl-L-carnitine (2 g) | 6 months |
| Choi et al (2013) [23] | Parallel | 59/59 | 57 (31–69) | 20.8 | Korean ginseng berry extract (1.4 g) | 8 weeks |
| de Andrade et al (2007) [24] | Parallel | 30/30 | 53 (26–70) | 20.0 | Korean red ginseng (3 g) | 12 weeks |
| Duračková et al (2003) [25] | Parallel | 13/8 | 47 (22–69) | 14.5 | Pycnogenol (120 mg) | 3 months |
| El-Sisi et al (2013) [26] | Parallel | 20/20 | 51 (40–60)b | 15.5 | Vitamin E (400 IU) | 6 weeks |
| El Taieb et al (2019) [27] | Parallel | 27/27 | 43 (-) | 14.1 | L-arginine (5 g) | 8 weeks |
| Forest et al (2007) [28] | Crossover | 53 | 46 (21–70) | 20.8 | Pomegranate juice (1.5 mm total polyphenol) | 4 weeks |
| Gentile et al (2009) [29] | Parallel | 10/10 | 55 (50–60)b | 15.6 | Propionyl-L-carnitine (250 mg); L-arginine (2.5 g); nicotinic acid (20 mg) | 12 weeks |
| Hong et al (2002) [30] | Crossover | 45 | 54 (-) | 12.7 | Korean red ginseng (2.7 g) | 8 weeks |
| Kim et al (2009) [31] | Parallel | 65/21 | 58 (33–79) | 14.1 | Panax ginseng (2 g) | 8 weeks |
| Ledda et al (2010) [32] | Parallel | 54/57 | 44 (30–50) | 15.2 | Pycnogenol (80 mg); L-arginine aspartate (2.8 g) | 6 months |
| Menafra et al (2022) [33] | Parallel | 51/47 | 51 (20–73) | 20.0 | L-arginine (6 g) | 3 months |
| Morano et al (2007) [34] | Parallel | 8/8 | 56 (45–70) | 19.0 | Propionyl L-carnitine (2 g) | 12 weeks |
| Mozaffari-Khosravi et al (2017) [35] | Parallel | 34/35 | 51 (25–55) | 16.2 | L-arginine (5 g) | 4 weeks |
| Najafabadi et al (2021) [36] | Parallel | 26/26 | 41 (32–57) | 18.4 | Vitamin E (100 IU); Korean ginseng (67 mg); Siberian ginseng (40 mg) | 6 weeks |
| Park et al (2019) [37] | Parallel | 21/20 | 57 (35–73) | 15.7 | Ginseng Radix Rubra, Cornus officinalis Sieb. et Zucc., Lycium chinense Mill, Daphnandra tenuipes, and Curcuma longa Linn (dose n/a) | 8 weeks |
| Safarinejad (2010) [38] | Parallel | 93/93 | 52 (35–60) | 9.8 | Coenzyme Q10 (300 mg) | 24 weeks |
| Stanislavov et al (2008) [39] | Crossover | 50 | 37 (30–50) | 14.0 | L-arginine aspartate (3 g); pycnogenol (80 mg) | 1 month |
| Stanislavov and Rohdewald (2015) [40] | Crossover | 50 | 37 (30–50) | 16.8 | L-arginine (1.92 g); pycnogenol (80 mg); citrulline (1.2 g); roburins (40 mg) | 4 weeks |
| Trebaticky et al (2019) [41] | Parallel | 32/21 | 49 (-) | 12.4 | Pycnogenol (120 mg) | 3 months |
| Yamashita (2018) [42] | Parallel | 22/22 | 48 (-) | 12.0 | Sanchi ginseng extract (62.5 mg total ginsenosides) | 12 weeks |
| Zenico et al (2009) [43] | Parallel | 25/25 | 36 (-) | 19.0 | Maca (2.4 g) | 12 weeks |
IIEF-EF, International Index of Erectile Function-Erectile Function.
aAntioxidant group/placebo group. bEstimated mean values. cIIEF-EF reported on a 6 to 30 scale.