I put 50mg of prop in delts and have pretty bad PIP for about 5 days every time.. Yet I continue to do it because I have to rotate sites.. 12 days sucks I've had that on my flute when I do 100mg of prop and tren in same syringe. Maybe just the high concentration mixed with the non filter and prop itself. Just keep letting it go so how it gets lol not really any other options for you