Sleep

Sleep is a fundamental biological process divided into non-REM (stages N1, N2, N3) and REM sleep, cycling approximately every 90 minutes across a normal night. Each stage serves distinct functions: slow-wave sleep (N3) supports glymphatic clearance, memory consolidation of declarative information, and growth hormone release; REM sleep supports procedural memory consolidation, emotional processing, and synaptic homeostasis. Chronic insufficiency of any stage produces measurable cognitive, metabolic, and immune consequences.

Sleep supplementation interventions fall into two mechanistic categories. Sleep onset agents act within 30-60 minutes of ingestion by modulating neurotransmitter systems: low-dose melatonin (0.3-0.5mg) shifts circadian signaling without suppressing endogenous production; L-theanine (200-400mg) promotes alpha-wave activity without sedation; apigenin (50mg) binds GABA-A receptors. Sleep architecture agents require 2-4 weeks of consistent nightly dosing to produce measurable change: magnesium glycinate (300-400mg elemental) improves sleep quality; glycine (3g) improves subjective and objective sleep metrics; phosphatidylserine reduces nocturnal cortisol elevation.

Foundational behavioral interventions consistently outperform supplementation. Consistent sleep-wake timing (varying less than 30 minutes), morning light exposure, limited evening blue light, cool bedroom temperature (18-20°C), darkness, and avoidance of alcohol and late caffeine represent higher-yield interventions than any supplement. Most commercial melatonin products are 10-30 times higher than physiologically optimal doses; the 0.3-0.5mg immediate-release formulation, difficult to find in retail, is preferred. Chronic use of high-dose melatonin may suppress endogenous production and cause morning grogginess; low-dose use shows safety over multi-year timeframes.