1-Methylhistidine Unit Converter

1-Methylhistidine (1-MH) is a methylated form of the amino acid histidine. It is measured in plasma or urine as part of an amino acid profile and serves primarily as a biomarker for dietary meat intake.

1-MH is released when the body digests anserine, a dipeptide found in animal muscle tissue. Because humans do not produce significant amounts of free 1-MH on their own, circulating levels reflect recent consumption of meat, especially poultry and fish.

1-MH is distinct from 3-methylhistidine (3-MH), which is an endogenous marker of muscle protein breakdown. Measuring both together helps clinicians separate dietary signals from muscle catabolism.

1-MH comes almost entirely from the diet. It is released when digestive enzymes break down anserine, a dipeptide concentrated in animal skeletal muscle, with the richest sources being poultry (chicken, turkey), fish (tuna, salmon), and to a lesser extent rabbit and duck. Beef and pork contain far less anserine and contribute relatively little to 1-MH levels.