L-carnitine, an amino acid, improves sperm quality and motility. Ferulic acid, an antioxidant found in Dong quai, also improves sperm quality. Sperm are highly susceptible to free radical or oxidative damage from environmental toxicants and natural aging. Vitamins C and E, green tea, and selenium are all potent antioxidants that help improve overall reproductive health. Zinc and B vitamins (B6, B 12 and folate) are critical nutrients in male reproductive systems for hormone metabolism, sperm formation and motility.