This is a summary from Wikipedia re research on ginseng, I've copied the annotations. Sounds like there is some potential benefit but that studies are ongoing:
"Ginsenosides, unique compounds of the Panax species, are under basic and clinical research to reveal their potential properties in humans. Possibly an adaptogen, ginseng remains under preliminary research for its potential properties or therapeutic effects, such as for respiratory illnesses, quality of life, influenza or fatigue in cancer patients. P. ginseng may affect cancer in animal models but this effect remains unclear. One study in laboratory animals showed possible effects of ginseng or its ginsenoside components on the central nervous system and gonadal tissues and another on penile erection.
Ginseng is known to contain phytoestrogens and may affect the pituitary gland to increase the secretion of gonadotropins. Other mice studies found effects on sperm production and the estrous cycle.
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12.^ Hong B; Ji YH; Hong JH; Nam KY; Ahn TY A double-blind crossover study evaluating the efficacy of korean red ginseng in patients with erectile dysfunction: a preliminary report. J Urol. 2002; 168(5):2070-3 (ISSN: )Department of Urology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea
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17.^ "A ginsenoside-Rh1, a component of ginseng saponin, activates estrogen receptor in human breast carcinoma MCF-7 cells". The Journal of Steroid Biochemistry and Molecular Biology 84 (4): 4638. 2003. doi:10.1016/S0960-0760(03)00067-0. PMID 12732291.