DLmethionine

DL-methionine is the racemic mixture of the two enantiomers of methionine, D-methionine and L-methionine. Methionine is a sulfur-containing essential amino acid in humans and many animals. In the racemate, the L-enantiomer is incorporated directly into proteins, while the D-enantiomer is not typically used by vertebrate protein synthesis. DL-methionine is commonly produced synthetically and is widely sold as a methionine source for animal nutrition because it can be cheaper and more stable than pure L-methionine. Some species can convert a portion of D-methionine to L-methionine, but the efficiency varies.

Uses: In animal agriculture, DL-methionine serves as a supplemental methionine source to meet essential amino acid requirements, supporting growth, feather production in poultry, and overall feed efficiency. It is especially important in diets based on cereal grains that are relatively low in methionine. In some markets, DL-methionine is used in feed formulations alongside other amino acids, such as lysine and threonine, to balance amino acid profiles.

Regulation and safety: When used as a feed additive at approved levels, DL-methionine is generally regarded as safe for target species. In humans, methionine requirements are met by dietary proteins; DL-methionine is not typically used as a direct dietary supplement for people, who usually consume L-methionine. Excessive methionine intake can disrupt sulfur amino acid balance and may elevate homocysteine levels in susceptible individuals, highlighting the need for balanced amino acid nutrition.