Oxymetholone (Anadrol)

What oxymetholone is and how it works

Oxymetholone is a synthetic derivative of testosterone, chemically a 17α-alkylated steroid. This modification protects the active substance from rapid breakdown in the liver and makes it effective as a tablet. In the US it was approved in 1972 as Anadrol-50, for anemia caused by deficient red blood cell production, for example in aplastic anemia or myelofibrosis. According to the FDA database, the product is no longer marketed there.

As with all steroids in this group, oxymetholone acts on the androgen receptor: it promotes protein synthesis and, according to the US prescribing information, stimulates the production of erythropoietin, the hormone for blood formation, in bone marrow failure. The prescribing information explicitly states that the anabolic and virilizing effects could never be completely separated. The high hormone level also suppresses the pituitary gland and thus the body’s own testosterone production. An overview of the whole substance group is given in the article Anabolic steroids.

What the studies show

Hengge 2003: HIV-associated weight loss

In a double-blind phase 3 trial with 89 HIV-positive men and women, participants on oxymetholone gained 3.0 and 3.5 kg respectively in 16 weeks, those on placebo 1.0 kg. Body cell mass rose, appetite and well-being improved. The most important side effect concerned the liver: in 35 and 27 percent respectively, ALT rose to more than five times the baseline value, and in no one under placebo.

Schroeder 2003: older men

31 men aged 65 to 80 received oxymetholone at one of two dose levels or placebo for 12 weeks. Lean mass rose by 3.3 and 4.2 kg respectively, under placebo by 0.0 kg; abdominal fat fell, maximal strength in the chest press rose by 8 and 14 percent respectively. At the same time, HDL cholesterol fell by 19 and 23 mg/dl respectively, and in the higher dose group ALT rose markedly.

Aramwit 2010: anemia in dialysis

In 24 patients on peritoneal dialysis, all of whom received erythropoietin, hemoglobin and hematocrit after 6 months of double-blind treatment were 12.9 g/dl and 38.1 percent under oxymetholone, and 11.0 g/dl and 32.8 percent under placebo. Weight rose; the main side effect was a rise in liver enzymes.

Pengthina 2022: aplastic anemia

In a retrospective analysis with 74 matched patients, 54.1 percent of the non-severe but only 13.5 percent of the severe cases responded after one year. For severe aplastic anemia, other treatments are now considered first choice; oxymetholone remains where these are not possible.

Velazquez 2004: liver tumors

A collection of all cases published up to that point found 133 liver tumors under androgens, in Fanconi anemia and in other diseases. Oxymetholone was the most frequent active substance; hepatocellular carcinoma occurred mainly under oxymetholone and methyltestosterone. How high the risk is cannot be calculated from this, because the number of all those treated is unknown.

Where the data stop

• Healthy users. There is no controlled study in healthy young people who want to build muscle with oxymetholone. All data on effects and harms come from sick or older people.
• Duration. The randomized trials ran for 12 weeks to 6 months. How the liver, blood lipids and heart develop over years is known only from case reports and case collections.
• Size of the tumor risk. That liver tumors occur is established; how often cannot be said for lack of a reference figure (Velazquez 2004).
• Strength and function. More lean mass does not automatically mean more everyday function. Only the study in older men measured strength, over 12 weeks.

Status, approval and legal

In Germany, oxymetholone is prescription-only (Ordinance on Prescription-Only Medicines, Annex 1). No finished medicinal product approved in Germany was found during research. In the US it was approved as Anadrol-50 from 1972 and was classified there as a Schedule III controlled substance; according to the FDA database, it is no longer marketed.

Oxymetholone is listed in the annex of the German Anti-Doping Act. Manufacture, trade and supply for doping purposes are prohibited, as are acquisition and possession of more than a small quantity for doping in sport; the penalty ranges up to three years, in serious cases up to ten. In sport it is on the WADA Prohibited List under S1.1 and is prohibited at all times.

Safety

Liver: oxymetholone is 17α-alkylated, and precisely this group puts the greatest strain on the liver. In the largest randomized trial, liver values rose to more than five times baseline in around a third. The prescribing information lists cholestasis with jaundice, rarely liver failure, as well as peliosis hepatis, that is, blood-filled cavities, and liver tumors, which can remain silent for a long time and only become apparent through bleeding into the abdominal cavity. It recommends regular liver tests.

Blood lipids and heart: HDL cholesterol falls, LDL can rise; the prescribing information calls these changes “very marked” and significant for atherosclerosis and coronary heart disease. With pre-existing heart, kidney or liver disease, fluid retention up to heart failure can occur. Anticoagulants such as warfarin act more strongly, with a risk of bleeding.

Hormonal axis: in men, testicular function is suppressed, the testicles shrink, sperm count falls; erectile dysfunction and breast growth have been described. In women, deepening of the voice, hair growth, acne, menstrual disorders and enlargement of the clitoris occur; according to the prescribing information, some of these changes persist even after immediate discontinuation.

Mental effects: the prescribing information lists excitation, insomnia and altered libido. For dependence, mood and mortality in non-medical use of steroids as a whole, see Anabolic steroids. Every step here should be preceded by a conversation with a doctor, with liver values and blood lipids as a fixed part of it.

Sources

• Prescribing information Anadrol-50 (oxymetholone), US label as of 08/2004 – indications, warnings on liver, blood lipids and virilization
• FDA, Drugs@FDA – Anadrol-50, NDA 016848: approval 1972, status discontinued
• Hengge UR et al., AIDS 2003 – RCT in HIV-associated weight loss, 89 patients, 16 weeks
• Schroeder ET et al., Am J Physiol Endocrinol Metab 2003 – RCT in 31 older men: lean mass, strength, HDL and liver values
• Aramwit P et al., Int J Clin Pharmacol Ther 2010 – oxymetholone plus erythropoietin in peritoneal dialysis, double-blind, 24 patients
• Pengthina W, Saelue P, J Blood Med 2022 – oxymetholone in acquired aplastic anemia, 74 patients
• Velazquez I, Alter BP, Am J Hematol 2004 – androgens and liver tumors, case collection
• German Ordinance on Prescription-Only Medicines (AMVV), Annex 1 – prescription requirement
• German Anti-Doping Act (AntiDopG), § 2 to § 4 and annex
• Prohibited List in sport 2026: S1.1 anabolic androgenic steroids, prohibited at all times (WADA Prohibited List)