Provilbol (Mesterolone 25 mg)

Provilbol (Mesterolone 25 mg) is Evolve Biolabs' oral DHT derivative, supplied as 50 tablets in sealed blister strips. It does not aromatise and binds sex hormone binding globulin, which is why it is studied as a free-testosterone support compound.

What Provilbol Is

Mesterolone is an orally active dihydrotestosterone derivative with a methyl group at carbon one and a keto group at carbon three. Those changes make it resistant to metabolism and unable to aromatise. Its defining pharmacological feature is affinity for sex hormone binding globulin: mesterolone occupies SHBG and displaces testosterone, increasing the free fraction of the hormone. Provilbol supplies the classic 25 mg strength across 50 tablets.

The History of Proviron

Schering introduced mesterolone in the 1960s under the Proviron name, positioning it for androgen deficiency and as an adjunct in male fertility. The interest was not mass building but free testosterone: mesterolone occupies SHBG and leaves more of the hormone unbound. That niche kept it in clinical use long after more potent anabolics had taken over the mass-gain market.

How It Works

Mesterolone acts directly at the androgen receptor and has no aromatisation pathway, so it adds androgenic signalling without contributing oestrogen. Its most distinctive action is on sex hormone binding globulin: by occupying SHBG it displaces testosterone and raises the free fraction. The compound is not alkylated at carbon seventeen in the usual oral-steroid manner, giving it a hepatic profile that differs from drugs such as oxandrolone, though the liver still handles its metabolism and urinary excretion.

What the Research Shows

• Mesterolone has been studied in androgen deficiency and male fertility.
• Research shows it increases free testosterone by displacing it from SHBG.
• Its lack of aromatisation is well documented.
• Comparative work places it among the mildest oral androgens.

Research Context

Mesterolone's interaction with sex hormone binding globulin is the focus of most of its research. By occupying SHBG, it raises the free fraction of testosterone without adding an aromatisable substrate, an unusual combination among oral androgens. Studies in male fertility have examined its effects on sperm parameters and free testosterone, with mixed results. Its different hepatic profile distinguishes it from drugs such as oxandrolone, although it is still metabolised by the liver and should be evaluated in that context.

Strength, Pack and Authentication

Each tablet contains 25 mg of mesterolone, with 50 tablets per pack. The tablets are sealed in moisture-resistant blister strips inside a printed, tamper-evident carton stating the compound, strength and tablet count. A verification code on the packaging can be checked against Evolve Biolabs' records, and the blister strips keep each tablet protected until use.

Buying Provilbol Online

Proviron is one of the most searched oral support compounds. If you are researching mesterolone, comparing 25 mg Proviron-style products or looking to buy Provilbol online from a verified Evolve Biolabs supplier, this page gives you the full specification, pack size, price and live stock status. Browse more Evolve Biolabs orals at NotNatty.