Ive been injecting from this source and while the quality of the products are great, this Test Cyp specifically, I noticed after I inject, the injection sight would be raised and inflamed, VERY much like a mosquito bite.

Or more specifically, I did a immunotherapy as a kid and a part of that process was testing what I'm allergic to. It's where they basically just poke you with a whole bunch of common allergens like pollen, cat, dog, whatever else.

The bumps and raises I got from those, which indicated I am allergic to what was on the poker, looks almost perfectly identical to the bump and raising from the injection site.

I don't think ths happened with other sources, or maybe I just never notice, but it got me wondering:

What exactly in these vials would cause an allergic reaction? I ask because maybe I'll switch to a source and be on the look out that they don't have said product in it.

Thanks.