Threonine is an essential amino acid. Your body cannot make it, so you must get it from food or supplements. It serves as a building block for proteins and directly supports the formation of collagen and elastin. These proteins help keep your skin and connective tissues strong. Threonine also aids antibody production, which supports normal immune function.
People take threonine to help maintain skin, joints, and digestion. It supports muscle maintenance and recovery after workouts by assisting protein synthesis. Some users also take it to help keep their mood balanced, though the evidence in this area is thin.
For the best uptake, take threonine on an empty stomach. Splitting the daily amount into smaller doses often works well. You can take it with food to avoid stomach upset, but that may reduce absorption slightly.
Large doses can cause mild digestive trouble in some people. Anyone with kidney or liver conditions should talk to a healthcare professional before using amino acid supplements.