I think I had this very first time I use HGH, with some light headedness, I cut back the dose so I start now with a lower dose for the first week or so and then I also upped my carb intake for those first few days and then I was fine
If it is really bothering you I would try lowering the dosage. If not then don't worry about it. I was always told to start small then go greater if I can handle it when I was looking into GH. Up to you brother