UPA HCG reaction?

Hi all, I used to get an unbranded vial of HCG from my source but the last one I received was the UPA HCG. Post injection every 3 times it getssore & tender to the touch, a little red & inflamed for a day or 2 & then just peters out. I got this once with the other HCG but otherwise there was no reaction. What could this be from do you guys reckon? :huh:

i used to get the same issue with pregnyl from the pharmacy, shoot IM. no issue.

Shot bro, I guess there wouldnt be an issue but its so much easier with a slin pin sub q :')

Slin pin I.M. Tada.

Seems obvious in hindsight :L thank you bro.