Whether goserelin or spiro, you need to take estrogen with it to feel good and avoid stuff like osteoporosis. Goserelin is an implant that lasts, I think, a few months and suppresses androgen production from your gonads (i.e. testicles). In other words, it's like being post-op except you're not, just chemically.
First few weeks though, androgen production goes up. But eventually, it just stops flat out!