Masteron-P Drostanolone Propionate

Masteron P (Drostanolone Propionate) – Royal Pharmaceuticals

• Category: Injectable Anabolic Steroid (Research Only)
• Brand: Royal Pharmaceuticals
• Content: 10 1 ml ampoules (150 mg drostanolone propionate per ml)
• Strength: 150 mg/ml
• Origin: United Kingdom
• Use Notice: Laboratory and analytical research only. Not for human or veterinary administration.

Scientific Overview

Drostanolone Propionate (“Masteron P”) is a short–moderate ester dihydrotestosterone (DHT) derivative widely used in androgen research.

As a non-aromatizing androgen, it permits investigation of anabolic signalling without estrogenic interference.

The propionate ester provides relatively rapid release from intramuscular depots, enabling tighter timing control compared with long esters.

Historically, drostanolone was evaluated in oncology research for estrogen-dependent breast cancer due to its anti-estrogenic characteristics. Today, it is predominantly studied in muscle physiology, endocrine pathways, and anti-doping chemistry.

Key Research Details

• Compound type: Anabolic-androgenic steroid (AAS), DHT-derived
• Ester: Propionate (short-to-moderate acting)
• Concentration: 150 mg/ml
• Form: Sterile oil-based injectable (IM) for research

Research themes include:

• Lean mass & muscle fibre signalling
• AR pathway activation & non-aromatizing androgen models
• Body-composition modulation and water-retention control
• Endocrine suppression & lipid-effect mapping
• Anti-doping detection window and metabolite identification

WADA status: Fully prohibited at all times (S1 – Anabolic Agents)

Mechanism of Action

Androgen Receptor (AR) Activation

Following intramuscular injection, drostanolone propionate is hydrolysed into free drostanolone.

The active steroid binds intracellular ARs, forming a complex that modulates transcription of genes tied to protein synthesis, nitrogen retention, and cellular hypertrophy.

Non-Aromatizing Androgen Profile

Drostanolone cannot convert to estrogen, allowing researchers to study:

• pure androgenic signalling
• androgen–estrogen balance without aromatase involvement
• androgenic anti-estrogenic effects in responsive tissues

Propionate Kinetics

The propionate ester produces a shorter half-life (~2–3 days in typical models), enabling rapid onset and easier experimental timing than long esters like enanthate.

Potential Research Applications

• Skeletal muscle anabolism & nitrogen balance studies
• Strength, power-output, and recovery models
• Body-composition research at controlled water-retention conditions
• Endocrine system mapping under strong DHT-derived androgens
• Comparative pharmacology vs. aromatizing or long-ester steroids
• Anti-doping detection method development and metabolite profiling

These outcomes are research observations and do not imply clinical utility.

Side Effects & Safety Considerations (Literature-Based)

• Androgenic signals: acne, oily skin, increased body/facial hair, scalp hair loss; virilisation in female models
• Lipid & cardiovascular markers: HDL, LDL, possible blood-pressure elevation and increased hematocrit
• Endocrine suppression: reduced endogenous testosterone, impaired spermatogenesis
• Hepatic & renal load: liver enzyme elevations and renal stress have been observed in AAS exposure models
• Neuropsychological changes: irritability, mood shifts, aggression in some androgen-exposure studies

Strict PPE, ventilation, documentation, and chemical-handling controls are required.

Compliance & Legal Status

Research-only compound; not approved for human or veterinary use.

Controlled/prescription-only in many jurisdictions.

Prohibited in all sports under WADA S1.

Buyers must ensure compliance with national AAS laws and laboratory regulations.

Technical Specifications

Research Use Only — Not for human or veterinary administration.