Nefiracetam never became a medicine; development stopped when the decisive stroke study did not deliver. What survives is one contested finding: in stroke patients who were also depressed, the higher daily dose improved motivation; a smaller repeat attempt found nothing. The claimed memory benefit rests on animal work. Dogs given very large doses developed kidney and testicular damage. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Serum creatinine | 0.7–1.0 mg/dL (men), 0.6–0.9 mg/dL (women) | Core kidney filtration marker |
| Estimated glomerular filtration rate | Above 90 mL/min/1.73 m² | Confirms filtration reserve before loading the kidney with metabolites |
| Blood urea nitrogen | 10–16 mg/dL | Rises early with reduced filtration or dehydration |
| Urine specific gravity and osmolality | 1.010–1.025; 500–800 mOsm/kg | Loss of concentrating ability was the earliest kidney signal in dogs |
| Alanine aminotransferase | 10–26 U/L (men), 8–22 U/L (women) | Liver health governs CYP3A4 clearance of the compound |
| Total testosterone (men) | 600–900 ng/dL | The animal toxicity signal began with falling testicular testosterone |
| Estradiol (men) | 20–30 pg/mL | Rose in dogs alongside the testicular lesion, making it a paired marker |
| Semen analysis (men planning conception) | Concentration above 15 million/mL, progressive motility above 32%, normal forms above 4% | Directly measures the endpoint damaged in both dogs and rats |
Cadence: Baseline before the first dose, repeated at 6 weeks and again at 12 weeks, then every 3–6 months if use continues past the studied window