Masteron-E 250 mg/ml Drostanolone Enanthate

Masteron E 250 mg/ml – Royal Pharmaceuticals

• Category: Injectable Anabolic Steroid (Research Only)
• Brand: Royal Pharmaceuticals
• Content: 10 1 ml ampoules (250 mg drostanolone enanthate per ml)
• Strength: 250 mg/ml
• Origin: United Kingdom
• Use Notice: Laboratory and analytical research only. Not for human or veterinary administration.

Scientific Overview

Drostanolone enanthate (“Masteron E”) is a long-acting injectable derivative of dihydrotestosterone (DHT).

Unlike testosterone, drostanolone does not aromatise to estrogen, making it valuable in research models studying androgen-driven body composition, hardness, and anti-estrogenic effects.

The enanthate ester provides prolonged release from intramuscular depots, extending experimental exposure windows.

Historically, drostanolone (mainly propionate) was investigated for certain breast-cancer indications due to its anti-estrogenic activity profile; however, therapeutic use has largely ceased due to androgenic side effects. It remains a key molecule in performance-enhancing drug (PED) research and anti-doping detection science.

Key Research Details

• Compound type: Anabolic-androgenic steroid (AAS), DHT derivative
• Ester: Enanthate – slow-release, long-acting
• Concentration: 250 mg/ml
• Form: Oil-based injectable (IM) for research use

Research themes include:

• Lean body mass & muscle hardness models
• Non-aromatizing androgen pathways
• Endocrine suppression & lipid-profile effects
• Comparative AAS pharmacology
• WADA anti-doping detection method development

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

Mechanism of Action

Androgen Receptor (AR) Activation

Drostanolone binds AR in muscle, bone, and connective tissues, promoting transcription of genes involved in protein synthesis and structural remodeling.

Non-Aromatizing Profile

Because drostanolone cannot convert to estrogen, it is frequently chosen in research where:

• minimal estrogenic activity is desired
• water-retention studies require control of aromatase pathways
• anti-estrogenic interactions with aromatising steroids are examined

Long-Ester Pharmacokinetics

The enanthate ester slows release from intramuscular depots prolonged half-life and stable exposure window, suitable for long-term investigations.

Potential Research Applications

• Lean-mass and muscle-density research in resistance-training models
• Endocrine & androgenic pathway mapping
• Anti-estrogenic support comparisons against aromatising steroids
• Body-composition studies requiring low water retention conditions
• Pharmacokinetic modeling of long-ester AAS
• Detection-window extension studies for anti-doping laboratories

These are research hypotheses only and not guaranteed effects.

Side Effects & Limitations (Literature-Based)

• Androgenic effects: acne, oily skin, increased hair growth, accelerated male-pattern baldness; virilisation in female models
• Endocrine suppression: decreased endogenous testosterone, fertility disruption
• Cardiovascular risks: lipid imbalance (HDL / LDL), increased blood pressure
• Hepatic/renal strain: AAS exposure linked to liver enzyme elevations and renal stress, though not 17--alkylated
• Neuropsychological signals: mood shifts, irritability, aggression patterns noted across AAS literature

These findings underline the importance of strict laboratory handling and prohibition of human use.

Compliance & Legal Status

Research-only chemical. Not approved by EMA, MHRA, FDA, or similar authorities.

Controlled substance in many jurisdictions; possession/use may be restricted.

Prohibited in all sports by WADA under S1.

Buyer must ensure full compliance with local laws and research regulations.

Technical Specifications

Research Use Only — Not for human or veterinary administration.