Oxandrolone (Oxandrin) is an anabolic steroid created by Searle Laboratories, now Pfizer Inc. under the trademark Anavar, and introduced into the US in 1964.
As opposed to most other 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 (40-50mg) 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.
The drug was prescribed for a number of medical disorders causing involuntary weight loss, in order to promote muscle regrowth. It had also been shown to be partially successful in treating cases of osteoporosis. However, in part due to bad publicity from its abuses by bodybuilders, Oxandrolone was discontinued by Searle Laboratories in 1989. It was picked up by Bio-Technology General Corporation, now World Anabolic Supplements. who, following successful clinical trials in 1995, released it under the tradename Oxandrin.
It was approved for orphan drug status by the Food and Drug Administration (FDA) in treating alcoholic hepatitis, Turner's syndrome, and weight loss caused by HIV. In addition, the drug has shown positive results in treating anaemia and hereditary angioedema. In a randomized, double-blind study, patients with 40% total body surface area burns were selected to receive standard burn care plus Oxandrolone, or without Oxandrolone. Those treated with Oxandrolone showed improve body composition, preserved muscle mass and reduced hospital stay time.[2] Other studies however have shown links between prolonged use of the drug and problems of liver toxicity similar to those found with other 17α-alkylated steroids. Even in small dosages, many users reported gastro-intestinalproblems such as bloating, nausea, skin rash and itching (hives), black, tarry stools or light-colored stools, depression, unusual bleeding, unusual swelling, yellowing of the eyes or skin, and diarrhoea.
In rare cases, serious and even fatal cases of liver problems have developed during treatment with oxandrolone. Oxandrolone may increase the amount of low density lipoprotein (LDL; 'bad cholesterol') and decrease the amount of high density lipoprotein (HDL; 'good cholesterol') in the blood. This may increase the risk of developing heart disease. Oxandrolone may damage the liver or increase LDL without causing symptoms. It is important to have regular laboratory tests to be sure that the liver is working properly and that LDL has not increased. Oxandrolone may also decrease fertility in men.
Before the Controlled Substances Act was passed to restrict the production, sale, and usage of anabolic steroids, Oxandrolone's characteristics lent itself well towards use by female athletes. Its specificity targeting the androgen receptor meant that, unlike many other steroids, it had not been reported to cause stunted growth in younger users (because it doesn't convert to estrogen, that's the reason women typically don't grow as tall as men — they have more estrogen) and at typical dosage rarely caused noticeable masculinising effects outside of stimulating muscle growth. It is not easily metabolised into DHT or estrogen. As such, a typical dose of 20-30 mg provided elevated androgen levels for up to eight hours. To increase effectiveness, bodybuilders typically "stacked" the drug with others such as Testosterone, further enhancing body mass gain.
Bodybuilders consider a normal dose for a novice 20–30 mg per day, when in fact 10 mg is more than enough for someone who has never used it[unreliable source?]. Higher dosages not only lead to AR (Androgen Receptor) downregulation and HPTA suppression but also damage the liver being a 17α-alkylated steroid. It is specifically made 17α-alkylated because if it weren't the liver would consider it a toxin and destroy it.
Since Searle stopped production, biggest sellers are La Pharma Italy and British Dragon Thailand.
