Glycine for sleep and performance: The amino acid you might be missing
Dr. Jonathan Pierce, PhD: Clinical Psychologist & Neuroscience Specialist
Dec 09, 2025 · 10 min read
Glycine may improve sleep quality by helping lower core body temperature by roughly 2–3°F—a key physiological trigger for entering slow-wave (deep) sleep—by increasing blood flow to the extremities to dissipate heat. That thermoregulatory “cooling switch” is why this overlooked amino acid can support deeper, more restorative sleep rather than just making you feel sedated. “We ...