Oxandrolone was created by the pharmaceutical company Searle in the early 1960s and sold as Anavar. Later it was marketed as Oxandrin and as generic tablets. In 2023, the US Food and Drug Administration withdrew approval for oxandrolone products, so it is no longer legally sold for human use in the United States. It remains available by prescription in some other countries, while most "Anavar" in gyms comes from unlicensed labs.
Like testosterone, nandrolone and stanozolol, oxandrolone is an anabolic-androgenic steroid (AAS). It was specifically designed to have a strong anabolic (tissue-building) effect and a weak androgenic (masculinizing) effect.
|
Property |
Detail |
|
Generic name |
Oxandrolone |
|
Brand names |
Anavar, Oxandrin, Lonavar, Oxandrolone generics |
|
Chemical name |
17β-hydroxy-17α-methyl-2-oxa-5α-androstan-3-one |
|
Molecular formula |
C19H30O3 |
|
Molecular weight |
about 306.4 g/mol |
|
Parent hormone |
Dihydrotestosterone (DHT) |
|
Form |
Oral tablets |
|
Common strengths |
2.5 mg and 10 mg |
|
Half-life |
About 9 to 10 hours (longer in older adults) |
|
Prescription status |
Prescription only where available; controlled substance in many countries |
Two structural features explain how Anavar behaves:
Oxandrolone binds to androgen receptors in muscle, bone and other tissues and switches on genes that drive growth and repair. In people who are losing weight because of illness or injury, this tips the body from a "breaking down" state back toward a "building" state.
Oxandrolone is derived from DHT, so it cannot be converted to estrogen. This means little water retention and no breast tissue growth from estrogen. It also binds androgen receptors in skin and scalp less strongly than testosterone, so masculinizing effects are weaker at medical doses. That said, "mild" is relative. At higher doses or with longer use, women can still develop permanent masculine changes, and men can still have their natural testosterone suppressed.
The 17-alpha methyl group slows the liver's ability to break the drug down, which can stress liver cells and, rarely, cause serious liver disease. Like stanozolol, oxandrolone also activates hepatic lipase, an enzyme that clears HDL. Even at modest doses, HDL can fall substantially within a few weeks.
With a half-life of around 9 to 10 hours, Anavar is usually taken once or twice a day. Its metabolites can be detected in urine for several weeks after the last dose.
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Medical use |
Why it helps |
|
Weight regain after major surgery, chronic infection or severe trauma |
Restores lean body mass and nitrogen balance |
|
Unexplained failure to gain or maintain weight (as an add-on) |
Promotes protein building alongside nutrition |
|
Muscle loss caused by long-term corticosteroid use |
Offsets the tissue-wasting effect of steroids like prednisone |
|
Bone pain linked to osteoporosis |
Supports calcium retention |
|
Severe burns (used in many burn units, often in children) |
Speeds healing and preserves muscle and bone |
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Turner syndrome and some growth delays (specialist use) |
Can modestly increase height gain |
|
HIV-associated wasting (studied, used in some places) |
Helps rebuild lean mass |
In every case, Anavar is meant to be an add-on to proper nutrition and medical care, not a stand-alone treatment.
Anavar is for patients with a specific medical reason for weight or muscle loss, prescribed and monitored by a doctor. Examples include:
Anavar is taken by mouth as a tablet, usually split into two to four doses a day because of its short half-life. It is normally prescribed for a short course, then stopped and reassessed.
The ranges below come from official prescribing information and are shown only to explain medical use. Your doctor decides your dose.
|
Patient group |
Usual dose (prescribing information) |
|
Adults |
2.5 mg two to four times a day; total usually 5–20 mg per day |
|
Older adults |
Often 5 mg twice a day |
|
Children |
Up to 0.1 mg per kg of body weight per day, set by a specialist |
|
Course length |
Usually 2 to 4 weeks, repeated intermittently if needed |
In burn care, specialists often use about 0.1 mg/kg twice daily, under close monitoring.
The original prescribing information carries a boxed warning, the most serious kind, about liver cysts (peliosis hepatis), liver tumors and harmful changes in blood cholesterol. Tell your doctor about all your health conditions and medicines before starting.
|
Medicine |
Possible effect |
|
Warfarin and similar blood thinners |
Major increase in bleeding risk; warfarin dose often needs large reductions and close INR checks |
|
Insulin and diabetes tablets |
Lower blood sugar |
|
Corticosteroids or ACTH |
More fluid retention |
|
Other liver-toxic medicines |
Higher risk of liver injury |
|
Other anabolic steroids |
Added liver, heart and hormonal risks |
Oxandrolone is banned at all times by the World Anti-Doping Agency (WADA). Athletes with a genuine medical need must obtain a Therapeutic Use Exemption.
Anavar's reputation as "safe" is misleading. Side effects are less dramatic than with some steroids at medical doses, but they are real, and the risk rises steeply at the higher doses used outside medicine.
Women are the group most likely to misuse Anavar because it is marketed as "female-friendly." Masculine changes can still happen and some are permanent:
Get medical help right away for:
People using Anavar for cutting or body sculpting often take several times the medical dose for weeks or months. This greatly increases the risk of liver damage, heart disease, hormone shutdown, infertility and lasting masculine changes in women. Because genuine oxandrolone is costly and scarce, black-market "Anavar" is frequently fake, under-dosed or swapped for cheaper and harsher steroids.
Rules change, so check your country's current laws before buying, importing or travelling with any steroid.
It was prescribed to help patients regain weight and muscle after surgery, severe infection, trauma or burns, to offset muscle loss from long-term corticosteroids, and to ease bone pain from osteoporosis.
Yes. Anavar is the original brand name for oxandrolone. Oxandrin was a later brand, and generics are sold under the chemical name.
Yes. It is an oral anabolic-androgenic steroid derived from DHT. It is unrelated to anti-inflammatory steroids such as prednisone.
In the US, FDA approval was withdrawn in 2023. It may still be prescribed in some other countries, but most products sold online or in gyms are unlicensed.
In medical use, weight and strength gains usually appear within 2 to 4 weeks when combined with good nutrition.
It is less masculinizing than many steroids, but women can still develop permanent voice changes, body hair and clitoral enlargement. It should only be used with a prescription.
It can. It is a 17-alpha methylated oral steroid and carries a boxed warning for liver cysts and tumors. Regular liver tests are essential.
It can contribute to male-pattern hair loss in genetically prone people, although less than some stronger DHT-derived steroids.
Yes, it suppresses natural testosterone in men, especially at higher doses or with longer use. Recovery can take weeks to months after stopping.
Some studies show reductions in abdominal fat in certain patient groups, but it is not an approved fat-loss drug and should never be used for that purpose.
Genuine oxandrolone is costly to make and hard to source legally. This is why counterfeit "Anavar" is so common.
It is best to avoid alcohol, since both put stress on the liver.