Amino acids, specifically, are generally safe to use every day, as long as they're not consumed in huge amounts. Because the nutritional needs of different people can vary widely, it's tough to say exactly what the upper limit might be for amino acids in general The recommended daily allowance for every 2.2 pounds of body weight for each of the essential amino acids are: Histidine: 14 milligrams. Isoleucine: 19 milligrams. Leucine: 42 milligrams.