L-arginine (精胺酸、精氨酸)是一種胺基酸，在堅果類、豆類最多。 L-arginine (精胺酸、精氨酸) 可以幫助產生一氧化氮(NO)，可以放鬆血管，所以可以降血壓。 L-arginine (精胺酸) 也可以增強胰島素敏感度。
服用方法： 每天 L-arginine (精胺酸、精氨酸) 3g x 3 次，期間是 3個月。
L-arginine (精胺酸、精氨酸) 效果：
RESEARCH DESIGN AND METHODS—A double-blind study was performed for 3 months. In the first month, patients were treated with their usual diet. Then they were randomly allocated into two groups. In group 1, patients were treated with diet plus placebo (orally three times per day) for 2 months. In group 2 patients were treated for 1 month with diet plus placebo (orally, three times per day) and then for 1 month with diet plus L-arginine (3 g three times per day). At the end of the first and the second month of therapy, patients underwent a euglycemic-hyperinsulinemic clamp combined with [6,6-2H2]glucose infusion. A total of 10 normal subjects underwent the same test as control subjects.
RESULTS—In group 1, no changes in basal cGMP levels, systolic blood pressure, forearm blood flow, glucose disposal, and endogenous glucose production were observed throughout. In group 2, L-arginine normalized basal cGMP levels and significantly increased forearm blood flow by 36% and glucose disposal during the clamp by 34%, whereas it decreased systolic blood pressure and endogenous glucose production by 14 and 29%, respectively. However, compared with normal subjects, L-arginine treatment was not able to completely overcome the defect in glucose disposal.
有疱疹者最好不要用 L-arginine (精胺酸、精氨酸)，可能會惡化。嚴重細菌感染如敗血症者也不適合。
某些情況，L-arginine (精胺酸、精氨酸) 也可能加速癌細胞的生長。