Oxandrolone, commonly known by brand names like Anavar o Oxandrin, is a synthetic anabolic-androgenic steroid (AAS) derived from dihydrotestosterone (DHT). It was first synthesized in the 1960s by Searle Laboratories (now part of Pfizer) and is one of the mildest oral steroids available.

Key Chemical and Pharmacological Facts

• Chemical Formula: C₁₉H₃₀O₃
• Molecular Weight: 306.44 g/mol
• Vida media: 9–10 hours (oral form)
• Mecanismo de Acción: Binds to androgen receptors in muscle and bone tissue, promoting protein synthesis, nitrogen retention, and red blood cell production. It has a high anabolic rating (322–630) and low androgenic rating (24), making it less likely to cause masculinizing effects compared to testosterone.

Evidencia: These properties are well-documented in pharmacological studies, such as those in Journal of Clinical Endocrinology & Metabolism (e.g., a 2004 study showing its efficacy in muscle wasting without strong virilization).

Approved Medical Uses

Oxandrolone is FDA-approved for:

• Promoting weight gain after surgery, chronic infections, or severe trauma.
• Offsetting protein catabolism in burns or osteoporosis.
• Treating growth failure in children (e.g., Turner syndrome) due to its minimal impact on growth plates.
• Alleviating bone pain in osteoporosis.

Dosing (Medical): Typically 2.5–20 mg/day for adults, divided doses; lower for children. Always under medical supervision.

Evidencia: FDA approval since 1964, supported by clinical trials like a 1997 study in Annals of Surgery demonstrating 20–40% lean body mass gains in burn patients.

Non-Medical/Performance Use

Bodybuilders and athletes misuse it for:

• Cutting cycles: Preserves muscle during calorie deficits, enhances vascularity, and mildly boosts strength.
• Stacks: Often combined with testosterone or Winstrol.

Typical Abuse Dosing: 20–80 mg/day (men), 5–20 mg/day (women) for 6–8 weeks.

Evidencia: Observational data from British Journal of Sports Medicine (2010s studies) links its popularity to low water retention and hepatotoxicity compared to other orals.

Efectos secundarios y Riesgos

Evidencia: A 2018 meta-analysis in Steroids journal reviewed 20+ studies, finding liver toxicity in <5% at <40 mg/day but rising sharply higher. Long-term use correlates with 2–3x cardiovascular risk per WHO data.

Legality

• A NOSOTROS: Schedule III controlled substance (prescription-only; illegal without Rx).
• Reino Unido/UE: Class C (possession legal, supply illegal).
• Sports: Banned by WADA (detectable 3–4 weeks post-use).

Evidencia: DEA scheduling since 1990 under Anabolic Steroid Control Act; WADA prohibited list updated annually.

Detection and Alternatives

• Urine Test: Metabolites detectable 3–4 weeks.
• Legal Alternatives: SARMs like Ostarine (less regulated, similar effects but unapproved for humans) or natural supplements (e.g., creatine, protein).

Caution: Not for self-medication. Consult a doctor for legitimate needs—bloodwork is essential to monitor lipids/liver. Misuse can lead to permanent damage.