You should be more specific in regards to a particular brand of prop. the only human grade prop that caused me pain was BM testopin. Like i said previously both viromones and testovis which are human grade are completely pain free.
I just started SYD Deca 300. I did the first shot in my left buttcheek and could harldy walk for a week. I ended up splitting it up a 1/2cc in each shoulder and it still hurts 5 days later.