Winstrol (stanozolol) for hereditary angioedema

Last updated Feb. 28, 2024, by Margarida Maia, PhD
Fact-checked by Joana Carvalho, PhD

What is Winstrol for hereditary angioedema?

Winstrol (stanozolol), now discontinued in the U.S., was a synthetic (lab-made) anabolic steroid that was approved as a prophylactic, or preventive, treatment to decrease the frequency and severity of hereditary angioedema (HAE) attacks.

Lundbeck, which held the rights to Winstrol in the U.S., decided to withdraw approval of its new drug application in 2010.

Therapy snapshot

How does Winstrol work?

Angioedema occurs when blood vessels leak fluid into the deep layers of the skin or the mucous membranes lining the surface of internal organs and cavities in the body, resulting in repeat swelling attacks.

In HAE types 1 and 2, the disease is due to mutations in the gene that provides instructions for making a protein called C1 inhibitor. This protein blocks an enzyme called kallikrein. When C1 inhibitor is faulty or missing, kallikrein becomes overactive, driving the excessive production of another signaling molecule called bradykinin. Too much bradykinin causes blood vessels to become more permeable, allowing fluid to leak into surrounding tissues.

The active ingredient in Winstrol, stanozolol, is an attenuated version of testosterone, the main male sex hormone. Like some other steroids, stanozolol increases protein anabolism, which refers to the production of proteins from their amino acid building blocks. As a result, stanozolol also increases the production of C1 inhibitor in the liver. This is expected to keep kallikrein’s activity under control, helping to reduce the frequency and severity of swelling attacks.

As an anabolic steroid that copies the way testosterone works, Winstrol can be abused to increase muscle mass, decrease fat, and improve physical performance. Its active ingredient, stanozolol, is a controlled substance under the U.S. Anabolic Steroid Control Act. It also is banned from use in sports under World Anti-Doping Agency (WADA) rules.

Who could take Winstrol?

Originally developed by Winthrop Laboratories, Winstrol was approved in January 1962 in the U.S. as a prophylactic treatment to decrease the frequency and severity of swelling attacks in people with HAE.

Who should not take Winstrol?

Winstrol was contraindicated, or not recommended, to:

• male patients with carcinoma (a cancer that forms in the skin or in the tissues lining internal organs) of the breast, or with known or suspected carcinoma of the prostate
• female patients with carcinoma of the breast and hypercalcemia (high levels of calcium in the bloodstream)
• patients with nephrosis (damage to the tiny filtering units in the kidneys that remove waste and excess fluid from the blood) or in the nephrotic phase of nephritis (kidney inflammation)
• women who were or might become pregnant.

The therapy’s prescribing information also came with a boxed warning noting that the use of anabolic steroids like Winstrol have been reported to be associated with liver problems and changes in cholesterol levels.

How was Winstrol administered in hereditary angioedema?

Winstrol was available as pink, round tablets to be taken by mouth. The recommended starting dose was 2 milligrams (mg) three times a day, then slowly lowered to 2 mg once a day or once every other day. Because Winstrol could have serious side effects, it was recommended patients be placed on the lowest possible effective dose.

Winstrol in hereditary angioedema clinical trials

A 1981 published study reported on the safety and efficacy of stanozolol in 27 people with HAE, ages 16 to 63, who had a history of incapacitating, monthly swelling attacks. All patients (15 females and 12 males) were started on stanozolol at a single daily 2 mg dose; their daily doses then varied from 0.5 to 6 mg. Adjustments were made at intervals of no less than two weeks, until the lowest possible effective dose was found. Some patients took 4 or 6 mg daily for up to 10 weeks, but all eventually ended up on a dose of 0.5 to 2 mg.

At daily doses of 2, 1, and 0.5 mg, patients experienced a cumulative rate of 0.07, 0.14, and 0.12 swelling attacks per week, indicating that the lowest possible effective dose was able to keep the disease under control. Four female patients experienced changes in menstrual patterns or developed male physical characteristics as side effects of maintenance treatment. Five male patients had elevated levels of the enzyme creatine phosphokinase in the blood, a possible sign of muscle tissue damage.

A 2015 review study concluded stanozolol can decrease the frequency and severity of swelling attacks in people with HAE. In some studies, treatment with stanozolol allowed most patients to enter into complete remission, where symptoms disappeared, or to remain nearly free of symptoms.

In a study with 13 women and nine men with HAE who took stanozolol at daily doses ranging from 0.5 to 2 mg for about 30 years, 10 experienced side effects. The most common side effects reported were hirsutism (excessive hair growth in unusual areas of a woman’s face and body), weight gain, changes in menstrual patterns, acne, and mood changes. These side effects were temporary and did not require specific treatment. Five patients had reduced levels of high-density lipoprotein (commonly referred to as “good” cholesterol), and two had elevated levels of triglycerides, another fat molecule found in the blood.

Common side effects of Winstrol

Common side effects associated with Winstrol included:

• new or worsening acne
• difficulty sleeping
• headache
• changes in sexual desire
• nausea and vomiting
• changes in skin color
• ankle swelling.

In male adults and adolescents, potential side effects of Winstrol included frequent or persistent erections, as well as the appearance or worsening of acne.

In women, possible side effects included hoarseness, acne, menstrual changes, and excessive hair growth on the face. The therapy’s prescribing information also stated that female patients should be closely monitored for such signs of virilization. Since some of these changes are irreversible, even after treatment discontinuation, it was recommended Winstrol be stopped or its dose significantly reduced at the first sign of mild virilization.

Liver problems

The use of an anabolic steroid can lead to peliosis hepatis, which happens when tissue in the liver, and sometimes in the spleen, is replaced with cysts (small sacs) filled with blood. Peliosis hepatis is usually asymptomatic, so it often goes unrecognized until the blood-filled cysts rupture, resulting in bleeding into the abdominal cavity, or when the liver starts failing. Blood-filled cysts usually disappear once the anabolic steroid is discontinued.

Liver tumors also have been reported. Most times, these tumors are benign and their growth relies on the presence of male hormones. Stopping treatment with the anabolic steroid can cause the tumors to shrink or stop growing. However, some liver tumors can be cancerous and grow silently until life-threatening bleeding into the abdominal cavity occurs.

Even low doses of an anabolic steroid like Winstrol can lead to cholestatic hepatitis (inflammation of the liver caused by a slowed or blocked flow of bile) and jaundice (yellowing of the skin and mucous membranes). If the liver stops working well, patients should be monitored closely and the anabolic steroid discontinued. If symptoms are mild, the dose of the anabolic steroid may be lowered instead.

Due to the potential of liver toxicity associated with the use of anabolic steroids, it was recommended that liver function tests be performed periodically.

Changes in blood cholesterol

The use of an anabolic steroid like Winstrol can cause levels of high-density lipoprotein (“good” cholesterol) to decrease and those of low-density lipoprotein (“bad” cholesterol) to increase. This raises the risk of atherosclerosis, which occurs when fatty deposits build in arteries, causing them to become narrower and making blood flow more difficult. It also increases the risk of a heart attack. For this reason, periodic checks of blood cholesterol levels were recommended for patients on Winstrol.

Short stature

It was not known if Winstrol was safe and effective in children with HAE. In children, however, the use of an anabolic steroid may make their bones mature faster but not grow taller, resulting in short stature as adults. The younger the age, the greater is the chance of a child using such a steroid not growing to full height. Children’s wrist and hand should have been monitored every six months for bone age to watch for changes in bone maturation.

Use with anticoagulants

Winstrol was thought to increase sensitivity to anticoagulants (blood thinners). Therefore, the dose of an anticoagulant might have had to be lowered to prevent bleeding.

Use in pregnancy and breastfeeding

Winstrol could cause birth defects in a fetus, so it was contraindicated in women who were or might become pregnant. It was not known whether Winstrol could pass into breast milk. Women who were breastfeeding were advised to consult their doctor before taking Winstrol.

Angioedema News is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.