Provi 25 Xeno Labs

Description

Proviron is an orally administered active androgen that contains a methyl group at the C-1 position, which provides unique properties different from testosterone and its derivatives used in androgen therapy. In addition, it is not metabolised to estrogen.

This difference explains the fact that in normal therapeutic doses in healthy men, Proviron slightly inhibits pituitary gonadotropin synthesis, and, accordingly, there is no decrease in spermatogenesis. Unlike other androgens, which replace endogenous androgens and suppress their synthesis, Proviron complements the action of endogenous androgens.

Also, unlike other orally active androgens, Proviron is well tolerated by the liver (which is probably due to the lack of a 17-alkyl steroid core substitute).

Pharmacokinetics

After administration, mesterolone is rapidly and almost completely absorbed over the dose range, which is 25-100 mg. A maximum serum concentration of 3.1 ± 1.1 ng / ml is reached 1.6 ± 0.6 hours after administration of Proviron.

Despite this, the level of the active substance in serum decreases with a final half-life of 12-13 hours. 98% of mesterolone binds to plasma proteins 40% of mesterolone to albumin and 58% to sex hormone binding globulin (hsBG).

Mesterolone is rapidly metabolised. The metabolic clearance rate from serum is 4.4 ± 1.6 ml – min -1 – kg -1 . The substance is not excreted unchanged by the kidneys. The main metabolites are 1α-methyl-androsterone; in the conjugated form it constitutes 55-70% of the metabolites and is excreted by the kidneys. The glucuronide to sulfate ratio of the main metabolite is about 12: 1. Another metabolite is 1α-methyl-5α-androstane-3α, 17β-diol, which accounts for about 3% of the metabolites excreted by the kidneys. No metabolic conversions to estrogens or GCS were observed. 77% of the mesterolone dose is excreted as metabolites in the urine and 13% of the dose is excreted in the faeces. Within 7 days, 90% of the administered dose was detected in the urine and faeces, of which 50% was excreted with the urine within the first 24 hours.

The bioavailability of mesterolone is approximately 3% of the orally administered dose.