Mucho changed

At the end of chapter 5, Oedipa is reunited with her husband. But, actually, she finds out that "the day she'd left him for San Narciso was the day she'd seen Mucho for the last time" (p118). She discovers that Hilarius had given him pills called LSD. He now is some complete different person, who thinks that he is an antenna sending his pattern out across a millino lives a night. The pills seem to have changed his entire being, and made him some sort of "calm" druggie, who believes the pills have changed his entire out look, and are good for him. But what were the pill's supposed to do? What was Hilarius trying to test when he gave them to Mucho? What was their purpose? And why would you test them on people, without knowing the results, and what would happen to the victim?