Prohexadione is a plant growth regulator. It inhibits the gibberellin plant hormone biosynthesis enzyme 3β-hydroxylase when used at concentrations of 0.1, 1, and 10 mM. It reduces the shoot length of peanut plants when applied at 0.5, 1.5, and 4.5 kg/hectare. Prohexadione also inhibits jumonji domain-containing 2A (JMJD2A) demethylase when used at a concentration of 1 mM and induces the differentiation of mouse neurospheres into neurons at 1, 1.5, and 2 mM. Formulations containing prohexadione have been used as plant growth regulators in agriculture.