Keeping it real, just be informed.
Some guys are going to get PIP: Post Injection Pain is often associated with virgin sites, poor technique, periodic "bad pins" even by us Old Farts.....some discomfort is inevitable.
Some guys n gals are just prone to reactions from "what everyone else uses" but these less fortunate souls have a rough time no matter what :-(
No or low BB
Then we have the bugs.....live pathogens, bacterias, silica dust and even the skeletons of "bugs" killed but not filtered out.
So now we have issues that can and will eventually cause one of our community a piece of flesh AKA an abscess drain or removal.
If you think your gear is dirty.....it probably is. If it's ONLY that one vial or brand is causing pain, heat, swelling and lumps....SHIT CAN IT!