In conclusion, we have demonstrated that PHIP allows for the production of highly polarized [1- 13 C]fumarate at a concentration of 45 mM in aqueous solution. Using relatively inexpensive and easily operated PHIP equipment, a 13 C polarization level of 25% was observed on [1-13 C]fumarate. For the reaction, we used 86% paraenriched hydrogen gas, meaning the polarization level could be increased to 31% by switching to 100% paraenriched hydrogen. Following the perfusion of lysed cells with the fumarate solution, metabolic transformation into malate was observed. This work paves the way for accelerated preclinical studies with hyperpolarized fumarate.