Source: Glycine Sleep RCT (Yamadera 2007) — 3 g before bed improved subjective sleep quality and next-day alertness.
A simple amino acid that's both a building block and a calming neurotransmitter.
Acts as an inhibitory neurotransmitter and lowers core body temperature to ease sleep onset.
Very safe, even at several grams before bed. No meaningful downsides.
| Per serving | |
|---|---|
| Typical branded single-ingredient product | $0.33 |
| Bulk powder at the clinical dose (500g, $25.97) | $0.16 |
Buying bulk powder instead of a branded bottle saves about 53% per serving.
Bulk price: $25.97/500g → Alt source: $7.99/500gEducational only — not medical advice. Grades and clinical doses are computed from public labels against sourced research (citations on the main site); prices last verified 2026-07-21. Expensive Powder has no sponsors; bulk links may earn an affiliate commission, which never affects a grade. Talk to a clinician before starting any supplement.