I was under the impression that HCG tells your balls to make testosterone. Why else would you take it?
It stimulates the testes, which is why they become larger, which is a result of their activity, which is why you take it on cycle to keep your natty test levels up, which is why you take it for PCT.
Am I not seeing something here?
If something is suppressive that means it's jumping in front on the bio-feedback loop between your glands and HPTA saying, "stop making testosterone!! We have enough from exogenous methods (such as injecting test)!
HCG short circuits that loop and fools your HTPA into thinking you don't have enough and thus gives your balls the go (if you will) to start producing test.
If I am understanding this correctly HCG is completely un-suppressive.