Both subcutaneous (SubQ) and intramuscular (IM) testosterone injections can work very well, and the best method usually comes down to personal preference, comfort, consistency, and individual response. SubQ injections absorb more gradually through fat tissue and may provide steadier hormone levels, while IM injections are delivered into muscle tissue, which has greater blood flow and may lead to quicker absorption and a faster peak. In individuals with higher body fat levels, IM injections may sometimes provide more predictable absorption, while SubQ injections can occasionally cause more local irritation, inflammation, or slower absorption depending on the person and injection technique. However, many overweight individuals still do extremely well with SubQ injections. Either method can commonly be performed with small insulin-style needles, even up to 29–31 gauge, although smaller needles may take longer due to the thicker oil-based nature of testosterone. At the end of the day, stable bloodwork, symptom improvement, proper technique, and choosing the method you are most comfortable maintaining long term are what matter most.