Proviron and Clenbuterol
Two ancillaries with unrelated mechanisms: an oral DHT derivative and a beta-2 agonist.
Proviron is mesterolone, a 1-methylated DHT derivative. Unusually for an oral it is not 17-alpha-alkylated, so it does not carry the hepatic profile of the alkylated class. It binds sex hormone binding globulin with high affinity, which is the basis of its use as an ancillary rather than as a mass-building compound.
Clenbuterol is not a steroid at all. It is a long-acting selective beta-2 adrenergic agonist, a bronchodilator by licensed indication, studied for thermogenesis and lipolysis through beta-adrenergic signalling. Its half-life is long at approximately 26 to 36 hours.
Beta-2 receptor downregulation with continuous exposure is well documented and is the pharmacological basis for the intermittent schedules described throughout the literature. It is a receptor-level effect rather than tolerance in the colloquial sense.
The two appear together here because both are ancillaries rather than because they share anything mechanistically.
UK stock
Proviron (Pharma) · £27out of stock
Quanta Pharma Proviron · £40in stock
Dispatched from UK stock, so orders do not cross a border and there is no customs process. Stock moves continuously - the product listing shows the live position. Every item carries a batch code that resolves through the manufacturer's verification tool.
Common questions
Is Proviron liver-toxic?
It is not 17-alpha-alkylated, so it does not carry the hepatic profile associated with that structural feature in other orals.
Is Clenbuterol a steroid?
No. It is a beta-2 adrenergic agonist, an entirely different class with an entirely different mechanism.
Why is Clenbuterol used intermittently?
Continuous beta-2 stimulation downregulates the receptor. That is documented pharmacology and is why continuous exposure loses effect.
What does Proviron do to SHBG?
It binds sex hormone binding globulin with high affinity, which raises the free fraction of other hormones present.
Full reference
For class, mechanism, pharmacokinetics and storage in detail, see the Proviron reference page.