Testosterone is a powerful hormone with notably prominent side effects

Much of which stem from the fact that testosterone exhibits a high tendency to convert into estrogen. Related side effects may therefore become a problem during a cycle. For starters, water retention can become quite noticeable. This can produce a clear loss of muscle definition, as subcutaneous fluids begin to build. The storage of excess body fat may further reduce the visibility of muscle features, another common problem with aromatizing steroids. The excess estrogen level during/after your cycle also has the potential to lead up to gynecomastia. Adding an ancillary drug like Nolvadex and/or Proviron is therefore advisable to those with a known sensitivity to this side effect. The anti-aromatase Arimidex, Femara, or Aromasin are a much better choices though. It is believed that the use of an anti-estrogen can slightly lower the anabolic effect of most androgen cycles (estrogen and water weight are often thought to facilitate strength and muscle gain), so one might want  to see if such drugs are actually necessary before committing to use. A little puffiness under the nipple is a sign that gynecomastia is developing. If this is left to further develop into pronounced swelling, soreness and the growth of small lumps under the nipples, some form of action should be taken immediately to treat it (obviously quitting the drug or adding ancillaries like Nolvadex).