i recommend IM as imo there is still some localised effects before it goes systemic.
500mcg is an ok starting dose. well you can expect to gain a little quality mass, everyone is different. You should appear fuller, achieve greater pumps, but will be more sore from workouts(increased DOMS). It depends where you are genetically, if stem cells are a limiting factor to your muscle growth. to me these peptides effects are more apparent on those that have reached their genetic potential(such as myself) and whose fibres are thick and mature.
i personally feel 1000mcg E3D works better, 1 hour pre-workout into muscles to be trained and used in conjunction with igf-1lr3.