Masteron (Methenolone Enanthate): The Mild Injectable, Examined
Research compounds for laboratory use only · not medical advice
What methenolone enanthate is, why the DHT scaffold never aromatizes, its ~10-day depot kinetics, and how the 100 mg/mL oil vial fits comparative androgen research.
Masteron is the quiet one of the injectable DHT family: no estrogen conversion, mild androgenic profile, and a two-week enanthate depot.
The molecule
Methenolone is oxandrolone’s injectable cousin — a Δ¹, 17α-methylated DHT derivative. Because the A-ring carries the double bond and the 17α-methyl is present, the molecule is not reduced by 5α-reductase further and is not an aromatase substrate. As the enanthate ester (C₂₈H₄₄O₃, ≈428 g/mol) it behaves as a classic oily intramuscular depot.
Kinetics: the ester master reference lists methenolone enanthate at ≈10 days, active fraction ≈73% — one tier below boldenone, well above the propionates. The clearance calculator turns that into a decay window for any starting timepoint.
Research context
Two comparative niches:
- Non-aromatizing androgen controls. When a study needs androgenic signaling without estrogenic confounding, methenolone is the standard injectable choice, alongside drostanolone.
- Doping-analysis targets. Its metabolites are part of long-term steroid testing panels, so it appears in LC-MS/MS method papers.
Practical notes
100 mg/mL oil solution, 10 mL vials — no reconstitution math. See Methenolone Enanthate for CAS and purity, and Masterol propionate for the short-ester sibling.
References: Kicman A.T., “Pharmacology of Anabolic-Androgenic Steroids.” Handbook of Experimental Pharmacology, 2008.
For laboratory research use only. Not medical advice.
FAQ
Frequently asked questions
What is methenolone enanthate?
Methenolone (Masteron) is a DHT-derived anabolic; the enanthate ester is the injectable depot form, releasing parent steroid over roughly ten days in intramuscular models.
Does methenolone aromatize?
No — like all 17α-methylated DHT derivatives it is not an aromatase substrate, which makes it a clean comparator in studies separating estrogenic from androgenic effects.
Enanthate versus propionate Masteron?
The enanthate is the slow depot (≈10 days); the propionate (Masterol) clears in a couple of days. The two coexist in the catalog as the long and short arms of the same molecule.
Why is it called Masteron?
Masteron was the original human pharmaceutical brand for methenolone, marketed in Germany in the 1960s; the injectable used the enanthate ester.
Keep reading
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Laboratory tools
Put it into practice
From the catalog
Reference compounds
Testosterone Enanthate
Long-ester testosterone. 250mg/mL in USP-grade carrier oil.
CAS 315-37-7
10mL vial · In stock
Drostanolone Propionate
DHT-derived propionate ester. Non-aromatizing standard.
CAS 521-12-0
10mL vial · In stock
Methenolone Enanthate
Mild DHT-derived enanthate ester.
CAS 303-42-4
10mL vial · In stock
Anavar
Oxandrolone. Mild anabolic profile.
CAS 53-39-4
100 tablets/bottle · In stock
For laboratory research use only