Here's a tip
If you want to avoid some of the pain of a Sust250 shot, drop the rediject into a glass of really warm water for a few minutes before you inject. The oil gets softer and won't harm the muscle as much. The injection will flow in a lot faster, but DON'T just go for it. Take at least 30-45 seconds to complete getting it all in there.
Once you've done it, massage the area for about 10 seconds to help the oil dissipate into the muscle. This really helps and you'll hardly feel sore at all the next day.
Good luck!