Desethyl Sacubitril=13C4 is the labelled, deuterated version of Desethyl Sacubitril which is an impurity in the synthesis of Sacubitril (S080895), an antihypertensive drug used in combination with valsartan. The combination drug, valsartan/sacubitril, known during trials as LCZ696 and marketed under the brand name, Entresto, is a treatment for heart failure.