Oxandrolone, also known as oxandrin, is a drug first synthesized by Raphael Pappo while at Searle Laboratories, now Pfizer Inc., under the trademark Anavar, and introduced into the United States in 1964. It is a synthetic anabolic steroid derivative of dihydrotestosterone with an oxygen atom replacing the 2 carbon and methylation in the 17 position.

Oxandrolone is primarily used for promoting weight gain, in catabolic situations such as chronic infections, extensive surgery, severe trauma, or cases where an individual has difficulty maintaining a normal body weight for their height and build. It’s also used to offset the protein catabolism associated with prolonged administration of corticosteroids, and for the relief of bone pain accompanying osteoporosis.

In addition, it has been used in the treatment of alcoholic hepatitis, Turner’s syndrome in girls, and for increasing muscle mass in patients with HIV/AIDS.

As an anabolic steroid, it can have significant side effects, especially when misused. Side effects can include liver damage, cardiovascular issues, changes in mood and behavior, and changes in physical appearance among others. It is considered a controlled substance in many countries due to its potential for misuse and addiction.