Testosterone Propionate also converts to both Estrogen (through Aromatization) and Dihydrotestosterone (through 5a-reduction). Most of the side effects people experience with testosterone use is actually from it’s conversion to these two substrates. Thus, hair loss , water retention, acne, and other side effects are possible with use of this drug. Conversion to these hormones is also responsible for some of testosterone’s ability to build muscle; therefore when many side effects are avoided with the use of ancillary compounds, some of the muscle building properties are also stunted.
Androgens stimulate protein synthesis in muscle, and they usually do not affect the overall synthesis in the organism. Androgens stimulate the production of red blood cells by synthesis and secretion stimulation of erythropoietin, direct stimulation of hematopoiesis in bone, marrow stimulation and inclusion of iron ions in the red blood cells. Although the use of androgens causes a significant increase in hematocrit and hemoglobin levels. At the same time in healthy men, when testosterone enanthate is applied in amounts of 200 mg per week, during 16 weeks cycle, the significant increase in the number of red blood cells and the increase in the hematocrit and hemoglobin were observed.
Some bodybuilders and athletes use trenbolone esters for their muscle-building and otherwise performance-enhancing effects.  Such use is illegal in the United States and many other countries. The DEA classifies trenbolone and its esters as Schedule III controlled substances under the Controlled Substances Act .  Trenbolone is classified as a Schedule 4 drug in Canada  and a class C drug with no penalty for personal use or possession in the United Kingdom .  Use or possession of steroids without a prescription is a crime in Australia .  The infamous "duchess" cocktail administered to Russian athletes at the Sochi Winter Olympics consisted of oxandrolone , a metenolone ester, and a trenbolone ester.