Clomiphene

Mixed estrogen agonist/antagonist. In the hypothalamus, acts as an estrogen antagonist — blocking the inhibitory effect of estrogen on GnRH pulsatility. This increases GnRH, which increases LH and FSH, which stimulates testicular testosterone production and spermatogenesis. In other tissues, partial agonism exists.

Non-steroidal oral compound. No ester. Isomeric mixture of enclomiphene (active) and zuclomiphene.

Clomiphene is used almost exclusively in post-cycle therapy protocols in performance settings. Like Tamoxifen, it blocks estrogen receptors in the hypothalamus and pituitary, removing negative feedback and stimulating LH and FSH secretion. This upstream stimulation drives endogenous testosterone production and supports spermatogenesis recovery. Some male athletes with documented hypogonadotropic hypogonadism use Clomiphene as an ongoing treatment to maintain testosterone levels without exogenous testosterone, which preserves fertility in a way that TRT does not.

Clomiphene is used alongside Tamoxifen in PCT protocols rather than as a performance stack compound. The combination of both SERMs provides stimulus at both the hypothalamic and pituitary levels and produces more comprehensive HPT axis recovery in many users than either alone. The standard sequencing involves HCG first to prime the testes, then the transition to Clomiphene and Tamoxifen together when HCG is stopped. Some practitioners prefer one SERM over the other based on individual patient response and side effect profile, and single-SERM PCT with either Tamoxifen or Clomiphene alone is also a common approach.

• Ovulation induction in anovulatory women — primary indication
• Male hypogonadotropic hypogonadism
• Male factor infertility
• Approved in India for infertility treatment

• Vision disturbances — blurring, floaters, photophobia — dose-dependent and reversible
• Hot flashes
• Mood swings — estrogen receptor effects in CNS
• Multiple pregnancy risk in women
• Ovarian cysts — in female use
• Headache, nausea
• Elevated LH:FSH ratio — may not be optimal for testicular function long-term

The vision disturbances associated with Clomiphene are dose-dependent and can be significant at the doses sometimes used in PCT protocols. Blurred vision, floaters, and photophobia are documented and in rare cases vision changes have persisted after discontinuation. Mood effects including depression, irritability, and emotional instability are reported more commonly with Clomiphene than with Tamoxifen and are believed to be related to the compound's mixed agonist-antagonist activity in the central nervous system. The elevated LH to FSH ratio that Clomiphene can produce may not be optimal for testicular steroidogenesis in all individuals.

WADA detection via urinary metabolite testing. Weeks detection window. Used to mask testosterone suppression in males.