I used test base as trt for roughly 2 years. Different brands/suppliers and both water and oil based. Subq would always lump up, get red and irritated for days to weeks after injecting and were talking tiny 8-20mg amounts here. If you dont mind the constant swelling or nodules, it can be done. It just got old for me... i think I went for a month trying to let my body adjust as it often does IM, but it never happened subq. It just sits under the skin and dissipates slowly which kinda defeats the purpose anyhow.