A mirror-image amino acid concentrated in the pituitary gland and testicles, where it appears to help signal testosterone production. One small short study in untrained men reported a rise; later studies in hard-training men found none, and at the doubled dose one found a fall. The evidence points weakly against benefit and is near-silent on long-term safety. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Total testosterone | 600–900 ng/dL | The primary outcome; everything else is secondary |
| Free testosterone | 15–25 ng/dL | The biologically active fraction; can fall while total stays flat |
| Luteinizing hormone (LH) | 4–8 mIU/mL | The pituitary signal the compound is meant to raise; separates a pituitary effect from a testicular one |
| Estradiol (sensitive assay) | 20–30 pg/mL | Detects the suppression documented at higher doses |
| Sex hormone-binding globulin (SHBG) | 20–40 nmol/L | Shifts can mimic or mask a real change in free testosterone |
| Hematocrit | 40–48% | Rises with any sustained androgen increase and thickens the blood |
| Prostate-specific antigen (PSA) | Below 1.0 ng/mL under age 50; below 2.5 ng/mL thereafter | Safety check before any androgen-directed intervention |
| Estimated glomerular filtration rate (eGFR) | Above 90 mL/min/1.73 m² | The kidney is the main route of clearance for this compound |
| Alanine aminotransferase (ALT) | 10–26 U/L | Screens for contamination-related liver injury in unregulated products |
Cadence: Baseline before the first dose, ideally two morning fasted draws a week apart; repeat at the end of the first twelve-day cycle, again at four weeks, and thereafter every twelve weeks for anyone continuing beyond a single cycle