Stanozolol
[CAS# 10418-03-8]

Identification

• Classification: API >> Hormone and endocrine-regulating drugs >> Androgen and anabolic hormone drugs
• Name: Stanozolol
• Synonyms: Androstanazol; Winstrol l; 17beta-Hydroxy-17-methyl-5alpha-androstano[3,2-c]pyrazole
• Molecular Formula: C₂₁H₃₂N₂O
• Molecular Weight: 328.49
• CAS Registry Number: 10418-03-8
• EC Number: 233-894-8
• SMILES: C[C@]12CC[C@H]3[C@H]([C@@H]1CC[C@]2(C)O)CC[C@@H]4[C@@]3(CC5=C(C4)NN=C5)C

Properties

• Density: 1.1±0.1 g/cm³, Calc.^*
• Index of Refraction: 1.573, Calc.^*
• alpha: 34 °
• Boiling Point: 490.8±45.0 °C (760 mmHg), Calc.^*
• Flash Point: 250.7±28.7 °C, Calc.^*

^* Calculated using Advanced Chemistry Development (ACD/Labs) Software.

Safety Data

• Hazard Symbols: GHS08 Warning
• Risk Statements: H361
• Safety Statements: P203-P280-P318-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Reproductive toxicity	Repr.	2	H361

• Controlled Substance: DEA Drug Code Number: 4000

Discovery and Applications

Stanozolol is a synthetic anabolic steroid derived from dihydrotestosterone (DHT), known for its performance-enhancing properties. Initially developed in the 1960s by Winthrop Laboratories, stanozolol quickly gained attention for its ability to promote muscle growth and improve athletic performance. It differs structurally from testosterone, with a unique pyrazole group attached to the A-ring, which reduces its androgenic effects while enhancing anabolic activity. This characteristic has made stanozolol a popular choice in both clinical and non-clinical applications, though it has also sparked controversy due to its misuse in sports.

The primary medical application of stanozolol is in the treatment of conditions that result in muscle wasting, such as chronic infections or long-term illnesses. Its ability to increase red blood cell production and enhance nitrogen retention makes it valuable in managing conditions like hereditary angioedema, a disorder that causes severe swelling of tissues. Stanozolol’s effectiveness in promoting protein synthesis has also made it useful in aiding recovery from burns, surgeries, or severe trauma. Moreover, it is sometimes prescribed for individuals with osteoporosis due to its ability to enhance bone density.

In veterinary medicine, stanozolol has been used to improve muscle mass, appetite, and overall strength in weakened or injured animals, particularly in horses. Its effects on promoting lean muscle growth and enhancing recovery from injuries have made it a valuable drug in equine treatment. However, its use in competitive sports, including horse racing, has led to regulations and bans due to its performance-enhancing properties.

The misuse of stanozolol in human sports became widespread in the 1980s and 1990s, when athletes sought to exploit its anabolic properties to enhance strength, endurance, and overall performance. Its low androgenic activity made it appealing to bodybuilders and athletes who wanted to minimize the risk of unwanted side effects such as hair loss or virilization in women. However, as stanozolol is classified as a controlled substance by anti-doping agencies, its use is prohibited in most competitive sports. The compound gained notoriety during the 1988 Summer Olympics when Canadian sprinter Ben Johnson was stripped of his gold medal after testing positive for stanozolol, a scandal that underscored the growing issue of steroid abuse in athletics.

Despite its controversy in sports, stanozolol remains an important compound in medical contexts where muscle wasting and anemia need to be addressed. Its capacity to boost protein synthesis and red blood cell production continues to offer therapeutic benefits in specific clinical conditions. However, ongoing concerns about its misuse have prompted tighter regulations and monitoring to prevent abuse while ensuring its availability for legitimate medical uses.

References

1971. Effects of Anabolic Steroids on Hormone-Binding Proteins, Serum Cortisol and Serum Nonprotein-Bound Cortisol. The Journal of Clinical Endocrinology and Metabolism, 32(2), 232-236.
DOI: 10.1210/jcem-32-2-232

2010. 2010 International consensus algorithm for the diagnosis, therapy and management of hereditary angioedema. Allergy, Asthma, and Clinical Immunology, 6, 24.
DOI: 10.1186/1710-1492-6-24

2014. Hair-based rapid analyses for multiple drugs in forensics and doping: application of dynamic multiple reaction monitoring with LC-MS/MS. Chemistry Central Journal, 8, 73.
DOI: 10.1186/s13065-014-0073-0