With an 1/2 insulin needle - I inject in my delts for any micro dosing, no more then 1/2 cc or .50 on the insulin needle. I micro dose my TRT, or Tren it works out good for me… I also use my delts to injects hcg or HGH it’s quick fast and easy no lumps as the delts have low amount or thin skin before hitting the muscle unlike some areas (glutes, quads). It just works better for me. Just my two cents!