Oxandrin (oxandrolone) is an oral synthetic steroid manufactured by Gemini Labs that can prevent hereditary angioedema (HAE) swelling attacks, but that can have side effects.

Generic versions of Oxandrin are also available.

How Oxandrin works

People with HAE experience recurrent attacks of swelling beneath the skin or under mucus layers in airways or the intestinal tract. This is because they have insufficient levels of the C1-esterase inhibitor enzyme. The shortage leads to a build-up of bradykinin, a molecule responsible for causing angioedema attacks.

Oxandrin is a man-made version of testosterone , a hormone that some HAE patients use off-label to prevent attacks. Oxandrin is thought to increase levels of C1-esterase inhibitor enzyme, although how it does it is unclear.

Oxandrin is usually used as a long-term attack prevention therapy rather than as a response to an attack that occurs. This is because it takes a few days for it to have an effect on C1-esterase inhibitor enzyme levels.

Oxandrin in clinical trials

Although no clinical trials have investigated Oxandrin’s ability to prevent hereditary angioedema attacks, the World Allergy Organization recognizes it as an option, and it is a part of the International Consensus Algorithm for HAE.

Two case studies found that a 6-year-old boy and a 14-year-old girl who took Oxandrin daily reduced the severity of their symptoms. Not all experts agree that children should receive long-term androgen treatment, however. A key concern is its side effects, such as reduced sex hormone production, or hypogonadism, in boys and menstrual irregularities in girls.

Additional details

Because of the significant side effects associated with Oxandrin, doctors usually start patients on the lowest dose that is able to stop angioedema attacks

Patients typically need to have their liver enzymes checked every six months and have a liver ultrasound while on the medication because it is known to cause liver toxicity and tumors.

Oxandrin may also have a side effect known as virilization, or development of male physical characteristics, in women. Virilizing side effects that have been reported include more body hair and changes in voice, mood, sex drive, and the appearance of breasts and genitalia.

Menstrual disturbances, acne, and headaches can also occur. Pregnant women should not use Oxandrin because it may affect the development of a fetus’s genitalia.

Other types of synthetic androgens that are used to treat hereditary angioedema are Danocrine (danazol) and Winstrol (stanazolol).


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