A drug used to help patients gain weight after injury, chronic infection, or severe illness. It belongs to the family of drugs called anabolic steroids.

Oxandrolone (Oxandrin) is an anabolic steroid created by Searle Laboratories under the trademark Anavar, and introduced into the US in 1964. It is taken orally, and unlike other steroids delivered in this manner, most of which are Class II steroids, the majority of its effects are due to reaction with the androgen receptor. In sufficient dosage, Oxandrolone is highly likely to bind well with the receptor, and is therefore a Class I steroid, while having few other side-effects.