Systems and methods are disclosed for increasing a nuclear spin polarization in a target compound. Nuclear spin polarization can be increased by obtaining the target compound or a precursor of the target compound. The target compound or precursor can include a first proton and a second proton sharing a singlet spin order and a third proton coupled at least to one of the first proton or the second proton. A target atom can be coupled to at least the third proton. The precursor can be placed within a mean magnetic field strength below 500 mT. A magnetic resonance (MR) pulse sequence can be applied to the precursor. the MR pulse sequence configured to transfer population from the first and second protons to the target atom, thereby imparting a non-equilibrium nuclear spin polarization of at least 1 %, 2%, 5%, 10%, or 20% to the target atom.