Sust still has to be injected frequently so I dont understand the switch? I run sust between cycles for my cruising TRT so I guess Im used to it, but maybe try 4 smaller injects spread out over your body, but I def stay away from quads with sust! I stick with delts, tri’s and glutes for sust.
im no expert but im on my 3rd cycle, first cycle of sust 250. i use 500mg a week, shoot twice a week. I take it in am hope in a hot shower for about 15 and have very little soreness the next day. If i cant take a shower all soke a clean rag in hot water and massage spot for about 3 min. seems to help.
I think some people are more sensitive to injections then others. I’ve never had a painful injection to the point where it would limit my mobility or kill me with pain. All I can say is try taking a hit shower or something before to warm and loosen the muscle, massage after injection, warm the oil and inject slowly.