L-Arginine HMB is the synthetic compound of L-Arginine and HMB, but not a mixture of L-Arginine and HMB Calcium. L-Arginine HMB is the synthetic compound of L-Arginine and HMB, no Calcium. Compared with the mixture of L-Arginine HMB Calcium, the L-Arginine HMB pound provides higher bioavailability. Remark: the product is not for sales in the patent protected area. L-Arginine HMB