To strengthen the anabolic properties of testosterone, more than 100 synthetic steroid derivatives have been described for human purposes. The anabolic effect promotes protein synthesis, muscle growth and erythropoiesis. In clinical practice, substances with anabolic effect are needed to overcome various catabolic states. However, none of these compounds are devoid of androgenicity. Androgenic and anabolic properties of anabolic steroids cannot be totally separated. Therefore, it is more appropriate to use the term anabolic androgenic steroids (AAS).
The oral bioavailability of oxandrolone is 97%.  Its plasma protein binding is 94 to 97%.  The drug is metabolized primarily by the kidneys and to a lesser extent by the liver .   Oxandrolone is the only AAS that is not primarily or extensively metabolized by the liver, and this is thought to be related to its diminished hepatotoxicity relative to other AAS.   Its elimination half-life is reported as to hours but is extended to hours in the elderly.   Approximately 28% of an oral dose of oxandrolone is eliminated unchanged in the urine and 3% is excreted in the feces . 
Serum testosterone, SHBG (Sex Hormone Binding Globulin), and LH (Leutinizing Hormone) will be slightly suppressed with low doses of Anavar, but less than with other compounds. FSH (Follicle Stimulating Hormone) , IGF1 (Insulin Like Growth Factor 1) and GH (Growth Hormone) will not be suppressed with a low dose of Anavar, but will actually be raised significantly (12)(13)(14) as you may have guessed, and LH will even experience a “rebound” effect when you stop using anavar (3) If your endocrine system and HPTA are functioning normally, you should be able to use anavar with minimal insult to it, and can even keep most of your values within the normal range (5).