There have been soviet human trials, however they were not as cruel as the experiments carried out on animals. Generally there´s a lot more on human experiments in America and Nazi Germany then there is on the USSR, but there was a poison research site named Laboratory 1, Laboratory 12 or simply Kamera (The Chamber) in which the KGB fed "enemies of the people" poison in order to come up with a tasteless, odorless agent that couldn´t be traced. https://en.wikipedia.org/wiki/Poison_laboratory_of_the_Soviet_secret_services

Sry I´ve just Wikipedia to undermine my claims made here, but search of JSTOR yielded no results and generally as I said there is little available as to Soviet human trials as mostly America and Nazi Germany were notorious in that fact.