Methenolone Enanthate
DHT-derived anabolic compound with mild profile and 10-day half-life. Resistant to aromatization.
Methenolone Enanthate
Methenolone Enanthate is a long-acting injectable formulation of methenolone, a 1-methylated derivative of dihydrotestosterone (DHT). The enanthate ester at the 17-beta hydroxyl position produces a plasma half-life of approximately 10.5 days, making this one of the most pharmacokinetically stable injectable anabolic compounds available. Methenolone is commonly known by the trade name Primobolan.
Structural Profile
Methenolone is structurally a 1-methyl, delta-1 modified dihydrotestosterone. The 1-methyl substitution provides resistance to enzymatic 3-alpha hydroxysteroid dehydrogenase deactivation in muscle tissue, while the delta-1 (1-2 double bond) modification further stabilizes the molecule. Crucially, because methenolone is already a 5-alpha reduced compound, it cannot be further reduced by 5-alpha reductase, and the 1-methyl group prevents aromatization to estrogen. The result is a compound with no estrogenic activity and minimal androgenic conversion in target tissues.
Pharmacokinetic Profile
The enanthate ester chain attached at the 17-beta position significantly increases the lipophilicity of the parent methenolone molecule, creating a sustained depot effect at the intramuscular injection site. Following administration, plasma esterases gradually hydrolyze the ester bond, releasing free methenolone into systemic circulation over an extended period. Peak serum levels are typically reached within 5-7 days of administration, with the long half-life producing stable plasma concentrations on a weekly injection schedule.
Mechanism of Action
Following hydrolysis, free methenolone binds with moderate affinity to the androgen receptor (AR), initiating conformational changes that activate androgen-responsive gene expression. Compared to testosterone, methenolone exhibits a lower anabolic-to-androgenic ratio (approximately 88:44 vs testosterone 100:100), translating to a milder pharmacological profile with significantly reduced androgenic side effect potential. The compound shows no SHBG binding affinity changes and does not aromatize to 17-beta estradiol under any physiological conditions.
Hepatotoxicity Profile
Unlike its oral counterpart (methenolone acetate), the injectable enanthate ester is not 17-alpha alkylated and therefore does not exhibit measurable hepatotoxicity at therapeutic concentrations. Clinical liver function markers (ALT, AST, GGT) remain within normal reference ranges during properly managed administration cycles.
Formulation
Biomedica Methenolone Enanthate is formulated at 100 mg/mL in pharmaceutical-grade carrier oil with benzyl alcohol (2% v/v) as bacteriostatic preservative and benzyl benzoate as co-solvent for solubility optimization. The formulation is prepared under aseptic conditions in our ISO Class 5 cleanroom suite and sterile-filtered through validated 0.22-micron polyethersulfone membranes before vial filling. Each batch undergoes complete pharmaceutical release testing including HPLC concentration verification (specification: 95-105 mg/mL), HPLC purity analysis (specification: ≥98%), sterility testing per USP <71>, bacterial endotoxin quantification by LAL assay (specification: <0.25 EU/mL), and particulate matter inspection per USP <788>.
Mechanism of Action
Methenolone Enanthate acts as a direct androgen receptor agonist following hydrolysis of the enanthate ester. As a 1-methyl DHT derivative it does not aromatize to estrogen and exhibits minimal 5-alpha reduction.
Quality Assurance
Every batch of Methenolone Enanthate produced by Biomedica undergoes the complete pharmaceutical release testing protocol before distribution. This includes HPLC compound identity confirmation and purity analysis (specification: ≥98%), concentration verification (specification: ±5% of label claim), sterility testing per USP <71>, bacterial endotoxin quantification by LAL assay (specification: <0.25 EU/mL), and particulate matter inspection per USP <788>. A Certificate of Analysis is issued for every production lot.
Authentication
Each unit of Methenolone Enanthate carries a unique authentication code on its outer packaging. This code can be verified instantly on our Authentication page to confirm the product is genuine Biomedica stock.