Across 3 studies of patients with erectile dysfunction, 2 reported moderate beneficial effects on erectile function, while 1 high-quality meta-analysis found a small neutral effect. The overall evidence direction is beneficial with a moderate effect size among positive studies, but findings are mixed and the most robust study does not support efficacy.
Caveats: Evidence base is small (only 3 studies) — conclusions should be considered preliminary. Many of the included studies did not reach statistical significance — effect may be smaller than the predominant direction suggests. The highest-quality study (meta-analysis) found a neutral effect, indicating potential overestimation of benefit in lower-quality studies.
Adverse events were recorded in 19 of 24 trials, with no significant differences between placebo and verum in placebo-controlled studies.
from: Herbal Dietary Supplements for Erectile Dysfunction: A Systematic Review and Meta-Analysissaffron and T. terrestris treatment produced mixed results
on both the IIEF-5 [MD 3.23 (95%CI 1.89, 4.58), p < 0.00001]
Korean ginseng, Pygnogenol and Prelox, Tribulus terrestris, Lepidium meyenii, L-arginine, acupuncture and lifestyle interventions were the more predominantly investigated treatments interventions for ED.