Table 1:

Overview of relevant studies on ginseng and L-arginine in the treatment of ED

Ginseng
Mechanism of Action (MOA): Increased NOS synthase activity and facilitate blood flow to corpora cavernosa
Author	Study Type	Outcome Measure	Results
Cho et al. (2013)	In vivo rat model	Rat intracavernosal pressure	Ginseng berry extract increases intracavernosal pressure in a dose-dependent fashion
Jang et al. (2008)	Meta-analysis	IIEF score	Some evidence exists that ginseng improves erectile function; however, low methodological quality makes it difficult to draw definitive conclusions
L-Arginine
MOA: Increase somatic concentration of NO
Moody et al. (1997)	In vivo rat model	NOS expression and MIP	Penile NOS and MIP are significantly increased in rats fed L-arginine
Chen et al. (1999)	RCT	O’Leary’s sexual function questionnaire	31% of men treated with L-arginine reported improved erectile function compared to 12% of men in the placebo group
Ledda et al. (2010)	RCT	IIEF-5 score	Men treated with L-arginine had improved erectile function on IIEF-5 scores compared to men treated with placebo
Chang et al. (2018)	Meta-analysis	IIEF score	Multiple RCTs provide evidence that arginine supplements can be recommended to patients with mild to moderate ED