I have tried doing exactly the same routine I do for peptides, but injecting BAC water alone. Same alcohol pads, same syringes, etc. I get no reaction at all when inject only BAC water.
I have bought sterile water but I have not tried reconstituting with sterile water instead of BAC water. I would have to use up the whole vial pretty quickly. And given that I don't get a reaction to BAC water, I don't expect the swap from BAC water to sterile water to solve the problem.
I thought maybe I was allergic to the filler they use in the lyophilized powder. But then, my histamine reactions don't follow quite the right pattern. When I started sema, I did not have a reaction for the first 2-3 injections. It started a bit later (maybe #4 or #5?) and got progressively worse. When i started tirz, I did not have a reaction to the first injection. Then a teeny-tiny reaction to the second. Then a clear histamine reaction to the third, and progressively worse from there. Same for reta: no reaction at first, then worsening over time. Makes me think I am actually reacting to the active ingredient. Dammit!