Enclomiphene Citrate Regret, Stopping, and Restarting: What Real Patients Report

What is documented about stopping?

Very little. The closest record is one small phase 2b trial. It enrolled 12 men with secondary hypogonadism who had previously used topical testosterone and compared enclomiphene with testosterone gel. One month after treatment ended, testosterone had fallen back to pre-treatment values [1]. During treatment, only the men on enclomiphene showed increased LH and FSH [1]. In the same study, sperm counts rose in 7 of 7 men on enclomiphene at 3 months [1]. The trials do not describe how men felt about stopping or about restarting.

Did the trials show that men felt better?

The phase 3 programme was built around a laboratory target. In ZA-301, 78.8 percent of men on enclomiphene (12.5 mg and 25 mg pooled, n=113) reached an average 24-hour testosterone of 300 to 1040 ng/dL. In ZA-302 the figure was 81.3 percent (n=134) [4][5]. FDA's 2022 review states that the phase 3 trials measured testosterone, LH, FSH and sperm counts, not symptom or quality-of-life improvement, and that this was a gap [2].

Which side effects made men stop?

The most frequent side effects were headache, hot flushes, nausea and muscle spasm. Reasons for stopping included blurred vision, muscle spasm, headache and aggression [5]. In ZA-302, headache was reported by 7 of 112 men on 12.5 mg versus 1 of 47 on placebo [5].

What does the clomiphene label say about visual symptoms?

The only FDA label in this area is Clomid's, which covers the two-isomer mixture clomiphene citrate and not enclomiphene alone. The label says that blurring or other visual symptoms such as spots or flashes increase in incidence with higher total dose or longer therapy. It says they are usually reversible, but that prolonged visual disturbances have been reported, some starting after discontinuation, and that they may be irreversible, especially with increased dosage or duration [6]. These are warnings for the mixture and are not proven for enclomiphene alone.

What doses have been studied?

The phase 3 trial protocols used 12.5 mg once daily, increased to 25 mg at week 6 if morning testosterone stayed below 300 ng/dL [4]. A phase 2 dose-finding study tested 6.25, 12.5 and 25 mg daily for six weeks [7]. There is no FDA-approved dose [2]. No source describes a dosing approach for restarting after a gap.