The list of possible effects depends on what hormones are being administered. Everyone is unique in their HRT treatment plan, or at least they should be. There is no one size fits all protocol for HRT.
Before beginning HRT, you should have a comprehensive lab drawn. Looking at all 33 hormones, metabolic and cardiovascular panels, plus an NMR lipid profile to understand your cholesterol pattern, is a necessary first step before beginning any hormone replacement therapy. Hormones administered without proper lab work and screening typically lead to a greater chance of side effects and a higher risk of complications.
If you can give some more details about your question, I can give you an answer closer to your specific needs.