Please read this on anavar in regards to the high doses which is above 10 mgs.
The drug is safe to use but again in high dosages will cause your own test to shutdown
Oxandrolone (Oxandrin) is an drug created by Searle Laboratories, now Pfizer Inc. under the trademark Anavar, and introduced into the US in 1964.
As opposed to anabolic steroids, Oxandrolone has two major advantages: First, it does not aromatize (convert to estrogen which causes gynecomastia - breast tissue). Second, it does not significantly influence the body's normal testosterone production (HPTA axis) at low dosages (10mgs). When dosages are high (this goes for any anabolic steroid) then your body feels that it has enough testosterone and it reduces the production of LH (luteinizing hormone) which no longer stimulates Leydig cells in testicles to produce testosterone therefore causing testicular atrophy (shrinking). Post Cycle Therapy (PCT) is of course needed for high dosages (40–50 mg) of this synthetic derivative of testosterone because as the dosage increases the influence on HPTA is bigger. Lack of PCT will of course lead to protein catabolism until body's normal testosterone secretion is back to normal.