Using a single amino acid supplement may lead to negative nitrogen balance. This can lessen how well your metabolism works. It can make your kidneys work harder. In children, single amino acid supplements may cause growth problems.
Single amino acid supplements aren't advised for people who eat an adequate amount of protein. You shouldn't take high doses of single amino acids for long periods of time.
Taking too much histidine may cause psychological issues. It may also lead to mood disorders.
People who are pregnant or breastfeeding shouldn't use histidine supplements.