Euphoria. Anybody else?

Everybody talks about anhedonia as a common side effect with GLPs, but I have predictable bouts of intense euphoria for the first day or two after every dose. I also get an insane energy boost that lasts from about day 2-5, and then fizzles out as the meds start to fall off. Anybody else? Any data or research, or theories, as to why this is happening?