I'd go 23g 1 1/2. Make sure you are not flexing you glute when you shoot. I stand on my left leg and lean on bathroon sick, my right leg is just resting on the ground. I then push on glute with hand to make sure the muscle in lose and not engauged at all. Then I push a drop out the needle to lubercate to tip. I use one hand to hold skin tight and break surface with one firm poke, Once its in slightly I make sure I'm inserting the needle straight and go in the rest of the way. generally leave about 1cm showing on needle. Quick draw to check for vien then inject slowly. Also be sure you DO NOT MOVE NEEDLE LEFT OR RIGHT WILL INJECTING you are just hollowing out a hole in you muscle, stay very still. IMO. GOOD LUCK HAPPY INJECTS<