Clomid (Clomiphene Citrate)

Clomiphene is a racemic mixture of enclomiphene (trans-isomer, ~38% of the drug) and zuclomiphene (cis-isomer, ~62%), which differ markedly in both activity and pharmacokinetics. Enclomiphene is the primary anti-estrogenic actor - it competitively blocks estrogen receptors in the hypothalamus and pituitary, preventing estradiol negative feedback and disinhibiting pulsatile GnRH release, which raises LH and FSH output. Elevated LH stimulates Leydig cells to produce testosterone; elevated FSH supports Sertoli cells and spermatogenesis. Zuclomiphene has weak estrogenic agonist activity and a much longer half-life (~14 days vs ~10 hours for enclomiphene), so it accumulates across repeated doses and contributes the estrogenic side-effect profile (mood, visual, libido effects) that distinguishes Clomid from pure enclomiphene.

Clomiphene is a racemic mixture of enclomiphene (trans-isomer, ~38% of the drug) and zuclomiphene (cis-isomer, ~62%), which differ markedly in both activity and pharmacokinetics. Enclomiphene is the primary anti-estrogenic actor - it competitively blocks estrogen receptors in the hypothalamus and pituitary, preventing estradiol negative feedback and disinhibiting pulsatile GnRH release, which raises LH and FSH output. Elevated LH stimulates Leydig cells to produce testosterone; elevated FSH supports Sertoli cells and spermatogenesis. Zuclomiphene has weak estrogenic agonist activity and a much longer half-life (~14 days vs ~10 hours for enclomiphene), so it accumulates across repeated doses and contributes the estrogenic side-effect profile (mood, visual, libido effects) that distinguishes Clomid from pure enclomiphene.

The tissue-selective activity pattern is similar to tamoxifen but distinct in emphasis - Clomid is a more potent HPT-axis stimulator at standard doses (50mg daily produces larger LH and FSH rises than 20mg tamoxifen), which is why it is often chosen when aggressive testosterone restoration is the goal, such as after prolonged anabolic suppression or in men with secondary hypogonadism who wish to preserve fertility rather than start TRT.

In breast tissue, Clomid acts as a partial antagonist but is generally less effective than Nolvadex for gynecomastia treatment - this is why a classic combined PCT runs both drugs (Clomid for maximal HPT stimulation, Nolvadex for receptor coverage at breast tissue). Clomid does not lower circulating estradiol - in fact estradiol typically rises during use because of the rising testosterone substrate available for aromatization.

What's safe to combine, and what belongs in a separate pin.

Storage. Store at controlled room temperature (20-25°C / 68-77°F). Protect from moisture and light. Keep in original container. Shelf life typically 4-5 years from manufacture date for tablets. Research-grade oral suspensions should be refrigerated after opening and used within 30-60 days. Keep out of reach of children.

Prescription medication (Rx) in the United States. FDA-approved brands: Clomid (Sanofi-Aventis), Serophene (EMD Serono), Milophene. Generic clomiphene citrate is widely available. Not a controlled substance. Off-label use in men for PCT or secondary hypogonadism is common but legally requires a valid prescription. Research liquid forms marketed for research purposes are not FDA-regulated for human use. Internationally classified as a prescription drug in most jurisdictions.