I agree with HGH, legit blockers and PCT usually obtained through your PCP (that is, if they are even willing) or though places like MG. There is basically zero FDA regulations when it comes to Supplement companies, so, they can promise whatever they want with no actual studies to back this up. However, votes and reviews do back up the sources that are on muscle guru's. Plus, from my experience, the price of blockers and test boosters, etc. are relatively the same or, in some cases cost more that the "real" stuff that us sources provide.