Peter Singer and Agata Sagan wonder:

If continuing brain research does in fact show biochemical differences between the brains of those who help others and the brains of those who do not, could this lead to a “morality pill” — a drug that makes us more likely to help? Given the many other studies linking biochemical conditions to mood and behavior, and the proliferation of drugs to modify them that have followed, the idea is not far-fetched. If so, would people choose to take it? Could criminals be given the option, as an alternative to prison, of a drug-releasing implant that would make them less likely to harm others? 

Will Wilkinson answers with a hearty no:

Moralities that manufacture heaps of happiness don't abolish selfishness, chauvinism, or status-seeking. They civilize and channel our baser drives into useful forms of expression. It doesn't matter if the gal who cures cancer is an asshole only in it for the glory. Indeed, we promise splendid everlasting fame to she who discovers the cure precisely to recruit the talents of glory-motivated assholes. A pill that turns assholes into helpful good sams may make a world where there's more willingness to help, but also fewer and shoddier tools for helping.