Important: this page is educational. Enclomiphene requires a clinician evaluation and is typically compounded in the United States.
What is enclomiphene?
Enclomiphene is the trans-isomer of clomiphene citrate, a selective estrogen receptor modulator (SERM). It is taken as a daily oral tablet or capsule. In the United States it is most commonly accessed through compounding pharmacies; the branded product Androxal completed Phase 3 trials but is not currently FDA approved.
How does enclomiphene work?
The hypothalamus uses estradiol as the brake on the male reproductive axis. Enclomiphene blocks estrogen receptors at the hypothalamus, removing that brake. The pituitary then releases more LH and FSH. LH signals the testes to produce more testosterone; FSH supports sperm production. The result is a rise in endogenous testosterone with maintained or improved fertility.
This is mechanistically the opposite of testosterone cypionate, which adds testosterone from outside and suppresses LH and FSH in the process.
How is enclomiphene dosed?
Typical dosing is 12.5 to 25 mg daily, taken in the morning or evening. Some men use every-other-day schedules to reduce side effects while maintaining response. Total testosterone usually rises within four to six weeks, and labs are repeated to titrate.
How long until enclomiphene works?
LH and FSH rise within a week. Total testosterone typically rises within four to six weeks. Subjective changes in energy, libido, and mood track roughly with serum levels and may take eight to twelve weeks to stabilize.
Trial data
Phase 3 trials for the branded Androxal product showed enclomiphene raised total testosterone into the mid-normal range in most secondary hypogonadal men while preserving sperm concentration and motility. In direct comparisons with topical testosterone, enclomiphene produced similar testosterone increases without the fertility suppression seen with exogenous therapy.
Who fits enclomiphene?
Enclomiphene is best suited to men with secondary hypogonadism (low testosterone with low or inappropriately normal LH/FSH) who want to preserve fertility, or men who prefer an oral option without injections. It is also used as part of a post-cycle protocol to restart the axis after exogenous testosterone.
For a full comparison, read TRT vs enclomiphene and the TRT fertility cost.
Side effects of enclomiphene
The most reported side effects are mood changes, visual disturbances (rare but well documented with the parent drug clomiphene), headache, and hot flashes. Most men tolerate enclomiphene better than racemic clomiphene because the enclomiphene isomer is responsible for the LH/FSH effect while the zuclomiphene isomer carries most of the mood and visual side-effect burden.
When enclomiphene is not enough
Enclomiphene relies on a functioning testis. In primary hypogonadism (testicular failure with elevated LH/FSH), the brake is not the problem and removing it produces little response. Enclomiphene also has a ceiling: men who need free testosterone deep into the upper-normal range often cannot reach it with a SERM alone. In those cases, exogenous testosterone with or without an HCG add-on is more appropriate.