L – arginine là ti?n ch?t c?a oxit nitric, m?t ch?t làm giãn m?ch máu. Vi?c t?ng c??ng s?n xu?t oxit nitric giúp c?i thi?n l?u thông máu ??n c? quan sinh d?c, t? ?ó c?i thi?n kh? n?ng c??ng d??ng ? nam gi?i.We do not see any motive why the resolution that our Evaluation offers (see Figures 3, four) is not really enough for investigating t