The first thing I felt was an increase in hunger. It started slowly but ended up being savage on me. I was very close to having to cut the dosage down.
From looking through the logs many noted increased hunger, some didn't get it. I don't know if anyone felt it as severely as I did. My food shopping bill was massive and I had to take food everywhere I went, even when I was only out of the house for a couple of hours.
After that the next effect I noticed was increased vascularity. You can see it in the photos in my log, I was noticeably fuller and more vascular five weeks later, despite being heavier.
That being said, I can't remember if I felt anything as soon as two days in.