AbstractThe seed of modern cultivars ofLupinus angustifoliusnormally contain less than 0.03% alkaloids. The acute oral LD50to rats of a prorata mixture of the alkaloids ofL. angustifoliusseed was found to be 2279 mg/kg. For lupanine the LD50by oral administration was 1464 mg/kg and by intraperitoneal injection 177 mg/kg. For 13‐hydroxylupanine the LD50by intraperitoneal injection was 199 mg/kg. Since these two alkaloids comprise about 85% of the total and are known to be rapidly cleared from the body it is suggested that the alkaloids in this species do not pose a health problem for ma