The deepest stage of sleep—when your body does most of its physical repair work and your brain consolidates memories.Slow-wave sleep (SWS, N3 stage) is characterized by high-amplitude, low-frequency (0.5–4 Hz) delta EEG activity. SWS is the period of maximal growth hormone secretion, tissue repair, immune function enhancement, and memory consolidation. Cortistatin is the most potent known endogenous promoter of slow-wave sleep. Galanin promotes sleep onset via hypothalamic circuits. GH secretagogue timing is typically recommended before bedtime to coincide with the natural nocturnal GH pulse during SWS.