Low red blood cell levels cause anemic like symptoms because it is the red blood cells that carry oxygen to the muscles. Mine have been steadily falling since I took Lupron 17 months ago (took it for only 4 months). Besides the anemic feeling I got short of breath and aching muscles with any significant exercise level because my low blood cell count limited oxygen flow to my body. My doctor has started TRT and I am slowly getting my strength back. This might take a year or more as it took that long to lose the red blood cells.