I read a comment on this sub from someone who pumps before using trimix. They said it gave them a notably thicker penis while hard. Thank you to whoever that was.

I have to inject because of nerve damage from a prostatectomy, and I use bimix rather than trimix. I tried water pumping before injecting last night. It was surprisingly thicker. My wife actually asked me to go slow because it was a bit too thick for her at first.

Over the course of the two hours or so that the injection lasts, the girth slowly returned to normal, but it was nice to be a bit thicker for a while.

Just something to consider if you already have to use a shot to have an erection.