Enclomiphene, an unapproved estrogen-blocking oral medication, prompts the brain to signal the testes to make more of their own testosterone. In men with low testosterone from weak brain signaling, evidence, mostly from its developer's trials, consistently shows it restores normal-range testosterone, and sperm production generally holds, though some men's counts fall. Symptom gains have not been shown, regulators flagged a blood-clot risk, and safety beyond about a year is unknown. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Total testosterone (morning) | 450–600 ng/dL (AUA guideline target) | Defines response |
| LH | About 1.7–8.6 IU/L (standard reference range) | Baseline confirms secondary cause |
| FSH | About 1.5–12.4 IU/L (standard reference range) | Sperm-production signal |
| Estradiol | About 10–40 pg/mL (standard reference range) | Safety check for estrogen effects |
| Hematocrit | Below 54% (Endocrine Society action threshold) | Safety check; stops or reduces use |
| PSA (men over 40) | No established target; change from own baseline is tracked | Safety check; prompts urologic review |
| ALT | About 7–56 U/L (standard reference range) | Safety check; liver disease contraindicates use |
| Triglycerides (fasting) | Below 150 mg/dL (standard reference range) | Safety check; a marked rise stops use |
| Semen analysis (if fertility matters) | Sperm concentration at least 16 million/mL (standard reference range) | Safety check; detects paradoxical decline |
Cadence: Baseline before starting; testosterone, LH and estradiol at 4–6 weeks after starting or changing dose; testosterone, estradiol, hematocrit and semen analysis at 3 months; then testosterone, hematocrit, estradiol and PSA every 6–12 months while treatment continues, adding triglycerides with a lipid-disorder history