Testosterone Propionate
Short-acting testosterone ester with a 2-day half-life, providing rapid onset and precise control of serum levels.
Testosterone Propionate
Testosterone Propionate is a sterile oil-based injectable preparation of testosterone esterified with propionic acid, presented at 100 milligrams per millilitre in a 10 mL multiple dose vial. It is the shortest-acting of the conventional testosterone esters and is selected where rapid onset and tight control of serum concentration are required.
Structural Profile
The compound is the 17-beta propionate ester of testosterone, with the molecular formula C22H32O3 and a molar mass of 344.49 g/mol, registered under CAS number 57-85-2. Esterification at the 17-beta hydroxyl position does not alter the pharmacological identity of the parent hormone; once the ester bond is hydrolysed in circulation, the liberated molecule is testosterone itself and is indistinguishable from endogenous hormone.
Esterification and Release
The propionate moiety is a three-carbon chain, the shortest ester in routine pharmaceutical use. Chain length governs lipophilicity and therefore the rate at which the compound leaves the intramuscular depot: the short propionate chain produces rapid partition into the aqueous phase of plasma, a swift rise in serum testosterone and an equally swift decline. Longer esters such as enanthate or cypionate behave in the opposite manner.
Pharmacokinetic Profile
The elimination half-life is approximately 2 days. Peak serum concentrations are reached within roughly 24 to 36 hours of intramuscular administration, after which levels fall steadily, so a short injection interval is required to maintain a stable plasma curve. The detection window for metabolites in urine extends to approximately 2 weeks, the shortest of the testosterone esters and a direct consequence of the rapid clearance.
Mechanism of Action
Following hydrolysis of the ester bond by plasma and tissue esterases, testosterone binds the cytoplasmic androgen receptor. The hormone-receptor complex translocates to the nucleus and interacts with androgen response elements on target DNA, upregulating transcription of genes governing structural protein synthesis in skeletal muscle. A proportion of circulating testosterone is converted by aromatase to oestradiol and by 5-alpha reductase to dihydrotestosterone, both of which contribute to the overall physiological profile.
Manufacturing and Sterility
Each production lot is released against the complete pharmaceutical testing protocol: HPLC identity confirmation and purity analysis with a specification of not less than 98 percent, verification of concentration against label claim within 5 percent, sterility testing in accordance with USP <71>, bacterial endotoxin quantification by LAL assay below 0.25 EU/mL, and particulate matter inspection in accordance with USP <788>. A Certificate of Analysis is issued for every lot.
Quality Assurance
Every batch of Testosterone Propionate 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 Testosterone Propionate 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.