A nine-amino-acid chain taken from sleeping rabbits fifty years ago, still without a confirmed gene or docking site. Human evidence is a handful of small, decades-old studies in severe long-term insomnia, split between improvement and no meaningful change. Aging findings come only from mice and rats. Side effects are mild; the supply is unverified. Evidence remains preliminary and unresolved. (Full Review)
| Marker | Target | Why |
|---|---|---|
| Slow-wave sleep percentage | 13–23% of total sleep time | The peptide's primary claimed endpoint |
| Sleep-onset latency | 10–20 minutes | Improved most consistently in the controlled trials |
| Overnight heart rate variability | Within 10% of personal 7-night baseline | Documented autonomic effect: lower variability |
| Resting overnight heart rate | Within 5 bpm of personal baseline | Heart rate rose in the one modern randomized study |
| Morning cortisol | 10–15 µg/dL at 08:00 | The mechanism most disputed between animals and humans |
| HbA1c | 4.8–5.3% | Human equivalent of the animal glycation finding |
| Fasting insulin | 2–5 µIU/mL | Detects the insulin-sensitizing signal reported |
| hs-CRP | <0.5 mg/L | Detects inflammatory or hypersensitivity response |
| ALT and AST | 10–26 U/L | Detects liver injury; rodent work claims protection |
| Complete blood count with differential | Eosinophils <3%; all indices within range | Rising eosinophils are the earliest allergic signal |
| Creatinine with eGFR | eGFR >90 mL/min/1.73 m² | Establishes renal reserve before dosing |
Cadence: Baseline before the first dose, with sleep measured over at least 7 consecutive nights. Sleep and autonomic measures run continuously and are reviewed at 2 and 8 weeks; the blood panel repeats at 8 to 12 weeks, then every 6 to 12 months.