No — stanozolol does not aromatise (no C4-C5 double bond for CYP19A1)
Route
Oral — 17α-alkylated (hepatotoxic at high dose/long duration)
QSC format
Research tablet kits ≥99% HPLC — Janoshik COA
Mechanism of Action
Stanozolol is unique among synthetic androgens — a pyrazole-derived steroid with the highest anabolic:androgenic ratio in the QSC catalog (320:30). The pyrazole ring at the A-ring of the steroid backbone confers both oral bioavailability and non-aromatisability. Stanozolol binds AR with moderate affinity (lower than testosterone) but also binds sex hormone-binding globulin (SHBG) competitively, displacing bound testosterone and increasing free testosterone in AR-containing tissues. SHBG binding competition is a pharmacologically distinct mechanism not shared by other androgens — making stanozolol uniquely useful for studying SHBG biology. Stanozolol also binds the progesterone receptor (PR) with measurable affinity and has established effects on fibrinolysis (PA:PAI-1 ratio) — making it a research tool for androgen effects on coagulation pathway biology.
Key Research Studies
Study
Finding
Danhaive & Rousseau 1988 (J Steroid Biochem)
Stanozolol SHBG binding affinity characterised — competitive displacement of testosterone from SHBG in vitro; foundational SHBG binding mechanism paper
Ferrer et al. 2007 (J Steroid Biochem)
Stanozolol induces apoptosis in mast cells via androgen receptor — ER-independent mechanism characterised
Wazir et al. 2017 (Transl Androl Urol)
Review of stanozolol fibrinolytic effects — PA/PAI-1 ratio, t-PA upregulation; relevant to research on androgen effects on coagulation
Research Protocol Design
SHBG competitive binding assay
Stanozolol 1-1000nM + purified human SHBG (radioligand or ELISA-based displacement). Compare SHBG binding affinity: stanozolol vs DHT vs testosterone vs nandrolone. Quantifies SHBG binding capacity independently of AR activation.
AR binding and transcriptional activation
Stanozolol vs testosterone: AR competitive binding assay (RBA), reporter gene assay (ARE-luciferase in 293T cells transfected with AR). Establishes relative potency for AR transcriptional activation despite non-trivial SHBG binding.
Fibrinolysis research
Stanozolol 50-200ng/mL in hepatocyte cultures (HepG2 or primary). t-PA and PAI-1 mRNA (qPCR) and protein (ELISA) at 24/48/72hr. Compare with testosterone and norethandrolone (historical SHBG-active compounds).
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Frequently Asked Questions
Does Winstrol (stanozolol) aromatise?
No — stanozolol does not aromatise to oestrogen. The pyrazole ring at the A-position of the steroid nucleus prevents CYP19A1 (aromatase) from converting it to an oestrogenic metabolite. This makes stanozolol the tool of choice for pure androgenic effects without oestrogen confounds.
What makes stanozolol pharmacologically unique?
Stanozolol uniquely combines high anabolic:androgenic ratio (320:30) + zero aromatisation + SHBG competitive binding. No other androgen in the QSC catalog has all three properties simultaneously. The SHBG binding mechanism is particularly valuable for research on SHBG biology.
What is the SHBG binding mechanism of stanozolol?
Stanozolol competitively displaces testosterone and DHT from SHBG — releasing bound androgens and increasing free testosterone fraction in tissues. This is a secondary mechanism that amplifies androgen action at AR-containing target tissues. Stanozolol is the primary research tool for studying SHBG competition in androgen biology.
