Yeah, the needles will cut the muscle up. You’ll have to be pretty shaky, but the up and down motion can cause slices. Sometimes if I get inpatient I’ll inject fast and that makes it itch. I found about 45-60 seconds a ML with a 25 gauge needle is perfect for me.I've done my quads a few times without an issue until last week. My right quad where I injected was super itchy a couple days after I injected and it lasted about 4 or 5 days. Do you think I moved the needle too much or something? It's fine now and definitely wasn't infected.