I would inject those into a fattier area like glutes or quads maybe even delts if you dont mind the pain As far as bis and tris, no way im stickin myself with a 20 gauge rediject in the bi, i can put a 22gauge but then it takes a little more patience and is still not appealing im not sure what is the thinnest gauge you can use for sust, I stick to mainly winny 25x1 arms shots