Testosterone Research: Biology, Compounds, and Protocols | QSC
QSC RESEARCH HUB — ANDROGENS & HPG AXIS
Testosterone Research: Biology, Compounds, and Research Protocols
Testosterone is the primary male sex hormone and the central compound in androgen receptor (AR) biology, HPG axis research, body composition studies, and anabolic pharmacology. This hub covers testosterone biology, the QSC testosterone and androgen catalog, research models, and links to individual compound pages.
Testosterone Biology
Property
Detail
Chemical class
C19 androstane steroid — derived from cholesterol via pregnenolone → DHEA → androstenedione → testosterone
Primary site of synthesis
Leydig cells of the testes (males); ovarian theca cells and adrenal cortex (females)
Regulation
LH from anterior pituitary → LH receptor on Leydig cells → cAMP → StAR protein → cholesterol transport → testosterone synthesis
Rat prostatic cytosol + [3H]-R1881 competing with test compound
Relative binding affinity (RBA) — AR pharmacology
IC50, Ki — relative AR affinity
Body composition (anabolic)
Castrated rat model → testosterone replacement dose-response (Levator ani + seminal vesicle weight)
Anabolic vs androgenic tissue selectivity (Hershberger assay)
Levator ani (anabolic) vs seminal vesicle (androgenic)
Hepatotoxicity (oral steroids)
HepG2 cells + 17α-alkylated androgen × 48hr
BSEP/MDR3 inhibition, cholestatic mechanism
MTT, LDH, ALT, BSEP mRNA
Stack Research Designs
TRT + HCG stack (ITT maintenance research)
Testosterone cypionate (HPG suppression arm) + HCG 250IU 3×/week. Compare to TRT-only control. Primary readouts: intratesticular testosterone (ITT by bilateral orchidectomy at study end → homogenisation → LC-MS/MS), testicular volume (ultrasound or orchidometer), LH/FSH, spermatogenesis (histology: spermatid count/tubule). This is the standard HPG suppression + Leydig maintenance research model.
AR selectivity fingerprinting
Compare: testosterone vs nandrolone vs stanozolol vs oxandrolone at equimolar doses in Hershberger assay (castrated rats, 10 days). Levator ani/seminal vesicle weight ratio for each compound. Generates anabolic:androgenic ratio data replicating published A:A benchmarks.
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Frequently Asked Questions
What testosterone compounds does QSC sell?
QSC sells testosterone cypionate (injectable ester) plus a full androgen research catalog: nandrolone decanoate, Dianabol, stanozolol, oxandrolone, superdrol, turinabol, and proviron — all as research compounds with Janoshik COA.
What is the difference between testosterone cypionate and other testosterone esters?
The cypionate ester (C8) produces a longer half-life (~8 days) than testosterone propionate (C3, ~2 days) or testosterone enanthate (C7, ~7 days). For research requiring sustained testosterone elevation without frequent dosing, cypionate is the standard injectable ester.
Do any QSC peptides stimulate testosterone production?
Yes — kisspeptin-10 (KISS1R → GnRH → LH → testosterone), HCG (direct Leydig LH receptor agonist), and HMG (FSH+LH activity). See the Peptides That Increase Testosterone research guide for the full HPG axis research framework.
What is the HPG axis and why does it matter for testosterone research?
The HPG (hypothalamic-pituitary-gonadal) axis controls testosterone production: GnRH (hypothalamus) → LH + FSH (pituitary) → testosterone (Leydig cells). Exogenous testosterone suppresses this axis; peptides like kisspeptin-10 and HCG can stimulate it. Understanding the axis is essential for designing testosterone-related research.
