Masteron (Drostanolone): The Complete UK Guide (2025)

Masteron — the trade name for Drostanolone — is the pre-competition steroid of choice for advanced bodybuilders. A DHT-derived compound that does not aromatise, Masteron produces a uniquely hard, dry, dense physique with a hardening and vascularising effect no other compound replicates. Originally developed as a breast cancer treatment, it became a staple of competitive bodybuilding in the 1980s and remains a top-tier finishing compound today.

Browse: Masteron • Drostanolone

What Is Masteron (Drostanolone)?

Masteron is a synthetic anabolic-androgenic steroid derived from dihydrotestosterone (DHT). Developed by Syntex in the 1950s, it was approved for medical use in the treatment of inoperable breast cancer in women. Its anti-oestrogenic and anti-proliferative properties made it effective in this context. In bodybuilding, these same anti-oestrogenic properties, combined with a hardening effect on the physique, make Masteron uniquely valuable during pre-competition cutting phases.

Because it is a DHT derivative, Masteron cannot aromatise — there is zero conversion to oestrogen. It also acts as an aromatase inhibitor in its own right, reducing circulating oestrogen levels when run alongside aromatising compounds like testosterone. This dual action (no aromatisation of its own + reduction of oestrogen from other compounds) gives Masteron its characteristic drying and hardening effect.

Masteron Propionate vs Masteron Enanthate

Feature	Masteron Propionate	Masteron Enanthate
Half-life	~2.5 days	~5–7 days
Injection frequency	Every other day (EOD)	Twice per week
Onset	Fast — felt within days	Slower — takes 1–2 weeks
Best for	Pre-competition; short cycles; quick side effect adjustment	Longer cycles; convenience
Classic form	Yes — the original Masteron	More modern alternative

➡ Masteron Propionate: Viogen Masteron Propionate 125mg | Evo Pharma Masteron P 120mg | Meta Pharma Masteron P 100mg | ZPHC Drostanolone Propionate 100mg

➡ Masteron Enanthate: Viogen Masteron Enanthate 225mg | Evo Pharma Masteron E 200 | ZPHC Drostanolone Enanthate 200mg | Driada Drostanolone Enanthate 200mg

How Masteron Works

• No aromatisation: As a DHT derivative, Masteron cannot convert to oestrogen. This removes water retention and gynecomastia risk attributable to the compound itself.
• Anti-oestrogenic activity: Masteron inhibits the aromatase enzyme and competes with oestrogen at the receptor level, effectively reducing oestrogen’s activity in the body. When run alongside a testosterone base, Masteron acts as a mild natural AI, reducing the need for pharmaceutical aromatase inhibitors like Anastrozole.
• SHBG binding: Masteron has high affinity for SHBG, reducing bound testosterone and increasing free testosterone bioavailability — amplifying the effect of your testosterone base.
• Hardening effect: Users report a visually harder, denser appearance to muscles, particularly at lower body fat percentages (<12%). This effect is most pronounced below 10% body fat.
• Moderate anabolism: Masteron has anabolic properties but is not primarily a mass-building compound. It shines as a finisher or stacking agent rather than a base compound.

Benefits of Masteron

• Muscle hardness and density: The most celebrated effect. Masteron creates a visually harder, more granite-like appearance to muscles that no other compound produces as distinctly.
• Anti-oestrogenic effect: Reduces oestrogen activity from aromatising compounds in the stack, meaning less water retention and potentially less pharmaceutical AI required.
• Vascularity: Reduced oestrogen and subcutaneous water makes veins more prominent and skin thinner over muscle bellies.
• Strength preservation: Maintains strength during a cutting phase or caloric deficit, where strength losses are common.
• Mood and libido: As a potent androgen, Masteron typically enhances mood, confidence, and libido — particularly valued when oestrogen is being suppressed by other means.
• No liver toxicity: Injectable Masteron is not 17-alpha alkylated and poses no hepatic risk.

Masteron Dosage Guide

Experience Level	Weekly Dose	Cycle Length	Notes
Beginner	300–400mg/week	10–12 weeks	Run with Test Propionate for a clean cutting cycle
Intermediate	400–500mg/week	10–14 weeks	Classic pre-competition dose
Advanced	500–700mg/week	12–16 weeks	Typically stacked with Winstrol or Trenbolone

Important: Masteron’s hardening effect is only visible at low body fat. Users above 15% body fat will not notice the visual hardening benefits. Masteron is best reserved for the final 8–12 weeks of a cycle when body fat is already significantly reduced.

Side Effects

• Hair loss: Masteron is a potent DHT derivative and one of the most hair-aggressive steroids available. Users with genetic predisposition to male pattern baldness may experience accelerated hair loss. This is the primary risk for most users.
• Acne: Androgenic stimulation of sebaceous glands can cause acne, particularly on the back and shoulders.
• HPTA suppression: Masteron suppresses natural testosterone production. Run with a testosterone base and follow up with proper PCT.
• Cardiovascular: Standard androgenic impact on cholesterol — HDL suppression, LDL elevation. Bloodwork every 6–8 weeks.
• No oestrogenic or progestogenic sides: No water retention, no gynecomastia, no prolactin issues.
• No liver toxicity from the injectable forms.

Best Masteron Stacks

• Classic Competition Stack: Test Prop + Masteron Prop + Winstrol: All three are short-ester, dry compounds. The ultimate pre-contest combination. Test Prop 400mg + Masteron Prop 400mg + Winstrol 50mg/day for 10–12 weeks.
• Test E + Masteron E (lean bulk / recomp): Longer esters for a 14–16 week lean-gaining cycle. Test Enanthate 500mg + Masteron Enanthate 400mg. Produces lean, dry mass with self-managed oestrogen.
• Test + Trenbolone + Masteron (advanced): The “holy trinity” of advanced cutting. All three are dry; together they produce extreme body composition changes. Requires careful management. See our Trenbolone guide.
• Test + Masteron + Primobolan (clean lean bulk): A mild, quality stack for experienced users who prioritise low side effects over extreme mass.

Shop Masteron Products

Product	Ester	Concentration
Viogen Masteron Propionate 125mg	Propionate	125mg/ml
Evo Pharma Masteron P 120mg	Propionate	120mg/ml
Meta Pharma Masteron P 100mg	Propionate	100mg/ml
ZPHC Drostanolone Propionate 100mg	Propionate	100mg/ml
Viogen Masteron Enanthate 225mg	Enanthate	225mg/ml
Evo Pharma Masteron E 200	Enanthate	200mg/ml
ZPHC Drostanolone Enanthate 200mg	Enanthate	200mg/ml
Driada Drostanolone Enanthate 200mg	Enanthate	200mg/ml

Browse: Masteron → • Drostanolone →

Frequently Asked Questions

Does Masteron work as an AI?

Yes, partially. Masteron inhibits aromatase and competes with oestrogen at the receptor, providing mild anti-oestrogenic activity. At 400–500mg/week alongside 400–500mg testosterone, many users find they need little or no additional AI. However, it is not a pharmaceutical aromatase inhibitor and should not replace Anastrozole in high-testosterone stacks.

What body fat percentage do I need for Masteron to work?

For the visual hardening effect: below 12%, ideally 8–10%. Above 15% body fat the compound still has anabolic and anti-oestrogenic benefits but the signature “Masteron look” will not be visible.

Is Masteron good for beginners?

Masteron can be used by beginners but is best appreciated by intermediate-to-advanced users who are already lean and experienced with compounds like testosterone. For a first cycle, testosterone only is the recommended starting point.

Masteron Prop or Enanthate — which is better?

Propionate is the classic choice for pre-competition use — faster onset, faster clearance. Enanthate is more convenient (twice weekly vs EOD injections) and equally effective for longer cycles where fast clearance is not a priority.

📚 Related Guides: Testosterone Complete Guide • Winstrol Guide • Primobolan Guide • Trenbolone Guide • PCT Complete Guide

For harm reduction and educational purposes only. Anabolic steroids are Class C substances in the UK. Consult a healthcare professional before any cycle.