The best places to inject insulin by pen or syringe (injection) insulin Inject insulin under the skin in the following places: ** In the abdomen under the skin, leaving a five-centimeter radius around the navel is not injected. Subcutaneous ** top and outside of the thighs. * Top outside Aleddan (arms). Share This: Facebook Twitter Google+ Stumble Digg Email ThisBlogThis!Share to XShare to Facebook