I am doing a cycle of deca and sust. When I started I would be very uncomfortable when i injected on either side(obviously). Now I am used to the pain and it doesn't really bother me anymore. Exept when I inject on the left side. It is extremely uncomfortable and sometimes gives me a little case of sust flu. Only happens when i inject on the left, but it has happened everytime exept for once. I am using the same general area every time to. I do everything the same for both sides. My buddy is doing the same cycle and hasn't noticed either side giving him more of a problem. What is going on? I have the feeling that there is nothing I can do but I am curious about what is going on since my buddy isnt having this problem.