It is only insignificantly hepatotoxic to liver and kidney because it is not a C17-alpha-alkylated substance. Mesterolone does not affect the creation of testosterone. This drug stimulates the body to produce testosterone. There is a risk of long-lasting and painful erections when taking this preparation if that is the case, it is mandatory to decrease the dose. Other side effects are hair loss and enlargement of the prostate; it may also raise the blood pressure.
The usual dosage for men is between 50 to 150 mg mesterolone daily. Period of 12 weeks is long enough time for effects of Mesterolone to reveal. Many bodybuilders favor to use it during definition period and pre-competition training, when particularly acceptable are low levels of estrogen and high levels of androgens. Mesterolone is recommended for use in combination with a low-power androgen (Oxandrolone, Methenolone, Stanozolol).