My very first time using Hgh was 2005. Serostim from a client who had a script so I knew it was real. I remember about a week into it I felt flu like symptoms. On most pharm GH inserts it says flu like symptoms can be a side effect although rare. I wonder if I was developing antibodies and that is what causes the symptoms? I’ve been off/on GH for 12yrs and my igf levels are high and I get results so I would think that means I didn’t develop antibodies but the flu like symptoms I get when on GH are odd. I don’t use much either. 2-4iu’s.