Overview
Enclomiphene is classified as a PCT (post-cycle therapy) and ancillary compound. Pure trans-isomer of clomiphene.
With a half-life of ~10 hours, Enclomiphene requires daily administration in most observed protocols. Taken orally, it has a bioavailability of approximately 95% via its primary route.
Half-life approximately 10 hours — shorter than the racemic mixture. Selective estrogen receptor modulator. One-compartment model.
Mechanism of Action
Enclomiphene's pharmacological activity involves the following key pathways:
Selective Estrogen Receptor Modulation
Enclomiphene acts as a selective estrogen receptor modulator, functioning as an antagonist in breast tissue while having varying effects in other estrogen-sensitive tissues.
Hypothalamic Feedback
By blocking estrogen receptors in the hypothalamus, Enclomiphene interrupts negative feedback, which can stimulate endogenous gonadotropin production.
Dosing Protocols
The following protocols represent commonly observed dosing patterns. These are observational summaries, not recommendations.
Dose
6.25 mg/day
Route
Oral
Frequency
Once daily
Duration
4-8 weeks
Dose
25 mg/day
Route
Oral
Frequency
Once daily
Duration
4-8 weeks
Frequently Asked Questions
What is Enclomiphene and how is it different from Clomid?
Enclomiphene is the isolated trans-isomer of clomiphene citrate — the specific component responsible for the anti-estrogenic, testosterone-boosting effects. Standard Clomid contains approximately 62% enclomiphene and 38% zuclomiphene (an estrogenic isomer that accumulates over time). By isolating only enclomiphene, the desired LH/FSH stimulation is maintained while eliminating the estrogenic accumulation that contributes to Clomid's side effect profile. Clinical comparisons have shown enclomiphene produces comparable testosterone elevation with statistically fewer adverse effects.
What is the half-life of Enclomiphene?
Enclomiphene has a half-life of approximately 10 hours, with peak plasma concentration reached in about 4 hours after oral dosing. This relatively short half-life means the compound clears the system quickly and does not accumulate significantly with daily dosing. Despite the short pharmacokinetic half-life, LH and testosterone levels have been observed to remain elevated for up to a week after discontinuation, reflecting the sustained downstream hormonal response rather than the drug's direct presence.
What is the typical Enclomiphene dosage?
Clinical trials have evaluated doses of 6.25 mg, 12.5 mg, and 25 mg daily. The most commonly reported dose is 12.5–25 mg per day, with 25 mg being the most studied dose for testosterone restoration. Some protocols use 25 mg taken 3–5 days per week rather than daily. Lower doses (6.25 mg) have shown measurable effects on LH and testosterone, making dose titration practical. Enclomiphene is typically available as compounded capsules since it is not yet FDA-approved as a standalone product.
Can Enclomiphene be used as a TRT alternative?
Enclomiphene is increasingly observed as an alternative to traditional testosterone replacement therapy, particularly for men who wish to maintain fertility. Unlike exogenous testosterone, which suppresses LH, FSH, and spermatogenesis, enclomiphene stimulates the body's own testosterone production while preserving the hypothalamic-pituitary-testicular axis. Head-to-head studies have shown enclomiphene raises total testosterone into the normal range at levels comparable to TRT, with the critical advantage of maintaining LH/FSH output and testicular function.
What side effects are reported with Enclomiphene?
Enclomiphene has been observed to produce significantly fewer side effects than clomiphene citrate. In clinical comparisons, overall adverse effects were reported in 13.8% of enclomiphene users versus 47% of clomiphene users. Decreased libido was observed in 8.6% versus 33.3%, reduced energy in 5.2% versus 16.7%, and mood changes were absent in the enclomiphene group versus 9.1% with clomiphene. The lower side effect profile is attributed to the absence of the estrogenic zuclomiphene isomer, which results in lower estradiol elevation.
How does Enclomiphene compare to Tamoxifen for PCT?
Both are SERMs that stimulate LH and FSH production to restore natural testosterone. A key difference is that tamoxifen has been observed to raise SHBG by approximately 20% and reduce IGF-1 by approximately 25% due to its estrogenic activity in the liver. Enclomiphene does not appear to elevate SHBG or suppress IGF-1 to the same degree, which may result in better preservation of free testosterone and growth factors during recovery. Enclomiphene's shorter half-life (~10 hours vs tamoxifen's 5–7 days) also allows for quicker clearance and more precise dosing adjustments.