4) Androgenic steroids (testosterone and analogues)
When you pick up a blood count, you will always find that males have a higher reference range for red cells and hemoglobin than females. That is mainly for 2 reasons, the first is that males don’t menstruate and the second is that men have much higher levels of testosterone, and testosterone is an anabolic steroid that stimulates cells to divide more rapidly and produce more protein. That is why it is used and abused by fitness models and medically useful to stimulate the bone marrow to produce more blood cells especially in the case of anemia.