The equivalence of the active and passive gravitational masses has been tested in the laboratory to an accuracy of about 5 parts in 10 5 . However, this level of sensitivity is not enough to answer the important question whether leptons generate gravity. We point out that some of the contemporary experiments aimed at re-determining the Newtonian gravitational constant, G, have reached the level of sensitivity required to provide the first meaningful result from a direct experiment on this important issue. Stronger constraints on the hypothesis that leptons do not generate gravity could be more decisively provided by still other G experiments if their aimed sensitivities are maintained in experiments with different sets of source masses.