Enclomiphene

Clomiphene citrate is a 50:50 mixture of two isomers with opposing pharmacological activities. Enclomiphene is the trans-isomer — a selective estrogen receptor antagonist at the hypothalamus and pituitary that drives HPG axis stimulation and endogenous testosterone production. Zuclomiphene, the cis-isomer, is an ER agonist with a long half-life that accumulates with extended use. Enclomiphene is zuclomiphene-free. CAS: 7599-79-3. MW 405.9 Da. The rationale for isolating the isomers is straightforward: racemic clomiphene mixes an ER antagonist with an ER agonist, and the pharmacological interference complicates both research interpretation and risk profile.

HPG Axis Activation

Estrogen suppresses GnRH pulsatility via negative feedback on hypothalamic neurons. Enclomiphene blocks estrogen receptors at the hypothalamic level, reducing that feedback brake. GnRH pulse frequency increases. The anterior pituitary receives more stimulation and responds by elevating LH and FSH. LH drives Leydig cell testosterone biosynthesis. FSH maintains Sertoli cell function and spermatogenesis. The axis activates from the top down, endogenously.

That's the fundamental distinction from exogenous testosterone: exogenous testosterone triggers negative feedback, suppressing LH and FSH and shutting down the HPG axis. Enclomiphene activates it. For studies examining HPG feedback dynamics, fertility preservation, or the biological differences between endogenous and exogenous testosterone production, that mechanistic distinction is the whole point.

Specifications

Storage: Room temperature, away from moisture and direct light.

Quality: HPLC purity analysis, mass spec identity confirmation, endotoxin testing on every batch. COA ships with every order. EU-based QC under CERTALAB S.R.L.

For research purposes only. Not for human consumption.