What Is Masteron

Last updated: June 8, 2026

TL;DR

Masteron (drostanolone propionate or enanthate) is a DHT-derived injectable anabolic steroid prized for hardening muscle, drying out water, and adding aggression on a cutting cycle. It does not aromatize, does not convert to estrogen, and produces zero water retention. Standard dose 300-500 mg/week for 6-10 weeks. Best used on lean physiques at sub-12% body fat – not a bulking compound. Suppresses natural testosterone, so always stacked with a test base.

What is Masteron?

Masteron is the brand name for drostanolone, a synthetic anabolic steroid derived from dihydrotestosterone (DHT). It was developed in the 1950s by Syntex for inoperable breast cancer treatment. Bodybuilders adopted it in the 1970s for its ability to harden the look of an already-lean physique. It comes in two main forms: Masteron Propionate (short ester, EOD injections) and Masteron Enanthate (long ester, 2x weekly injections).

What does it actually do?

Three signature effects:

• Hardens muscle – because Masteron does not retain water and binds the androgen receptor in dry tissue, it produces a chiseled, grainy look impossible without it
• Mildly anti-estrogenic – drostanolone competes with the aromatase enzyme, reducing estrogen activity even from other compounds in the same cycle
• Strength and aggression boost – DHT-derived compounds always sharpen the mental edge and increase aggression on heavy lifts

It is not a mass-building compound. You will not gain 10 kg of muscle on Masteron – you will look 5 kg drier on whatever muscle you already have.

What is the standard dose?

Cycle dosing protocols:

• Beginner: 300 mg/week split into Mon/Thu injections (Enanthate) or EOD (Propionate)
• Intermediate: 400 mg/week
• Advanced: 500-700 mg/week, only with extensive prior experience

Going above 500 mg/week rarely produces proportional gains in look – just deeper test suppression and stronger hair-loss potential.

How long should a cycle be?

Six to ten weeks. Most pre-contest bodybuilders run Masteron in the final 8-12 weeks of contest prep, ramping the dose up as the show approaches. For non-competitors, 8 weeks of 400 mg/week paired with test gives the visual recomp without becoming a year-round habit. Longer cycles deepen suppression and elevate DHT-related side effects.

Does it cause estrogen problems?

The opposite – Masteron mildly lowers estrogen activity through aromatase competition. Many users report better mood and lower estrogen sides when adding Masteron to a test+deca or test+tren stack. It does not eliminate the need for an AI on heavy test cycles, but it can reduce the AI dose needed.

What about hair loss and prostate?

This is the real catch. As a DHT derivative, Masteron carries significant androgenic activity. Users genetically prone to androgenic alopecia (MPB pattern) accelerate hair loss noticeably. Prostate enlargement at 500+ mg/week is documented but rare in healthy users under 40. Finasteride does NOT block Masteron because the compound is already past 5-alpha reductase – finasteride is useless here. Topical RU58841 is the only realistic hair-loss countermeasure.

What bloodwork should you run?

Required panel:

• Total testosterone, free testosterone, LH, FSH, SHBG, estradiol (sensitive)
• Lipid panel – LDL rises, HDL falls hard on Masteron
• Hematocrit, hemoglobin – rises noticeably
• Liver enzymes ALT/AST – usually fine at standard doses
• PSA if over 40

Baseline at week 0, mid-cycle at week 4-5, post-cycle at week 10-12. We cover the full panel and what each marker means in our bloodwork guide.

What should you stack it with?

Masteron is always a partner compound – never run alone. Common stacks:

• Cutting: Test Prop 300 mg + Masteron Prop 400 mg + Anavar 50 mg/day, 8 weeks
• Contest prep: Test Prop 200 mg + Mast Prop 400 mg + Tren Acetate 300 mg + Winstrol 50 mg/day, last 6 weeks
• TRT add-on: 200 mg/week Mast E on top of TRT dose test for a recomp boost

Stacking with bulking compounds (deca, dbol) defeats the point – the water retention from those covers any hardness Masteron would bring. See our best stacks guide for non-Mast options.

How fast does it work?

Propionate ester: noticeable hardening within 2-3 weeks. Enanthate ester: 4-5 weeks for peak effect. The visual effect is gradual – week-by-week dryness rather than a single dramatic shift. Pre-contest bodybuilders time the propionate version specifically because they can stop 5 days before show and still keep the look.

What are the realistic side effects?

At 300-500 mg/week:

• Hair shedding in genetically prone users (most consistent complaint)
• Oily skin and back acne in DHT-sensitive users
• LDL rise, HDL drop (often 20-30%)
• Test suppression to 10-20% of baseline by week 4
• Mood: more aggressive, more focused, occasional irritability
• No water retention, no gyno, no bloat

Is Masteron legal in Canada?

Drostanolone is a Schedule IV controlled substance under the Canadian Controlled Drugs and Substances Act – prescription-only for medical use, illegal for performance enhancement. Personal possession is rarely prosecuted but trafficking carries serious penalties. Full classification details are at the CDSA reference page.

Sources

• Llewellyn W. Anabolics. Body of Science Publishing, 11th ed.
• Kicman AT. Pharmacology of anabolic steroids. Br J Pharmacol, 2008.
• Health Canada Controlled Drugs and Substances Act schedules.