Glycine for Sleep: The 3,000mg Dose That Deepens Rest Without Sedation
Reviewed by the N of 1 Science Team | Updated March 2026
Glycine improves sleep by lowering your core body temperature, the same signal a warm bath gives your body before bed. It does this through peripheral vasodilation rather than sedating your nervous system, so you wake up more alert, not groggy. Four randomized controlled trials used the same 3,000mg dose before bed and reported better subjective sleep quality and less next-day fatigue. RCVR delivers that exact 3,000mg, plus the magnesium that deepens slow-wave sleep alongside it.
3,000mg
Exact dose from 4 RCTs
0.1-0.3C
Core temp drop it triggers
0g
Added sweetener (glycine is sweet)
How Glycine works for sleep
Oral glycine crosses the blood-brain barrier and acts at the suprachiasmatic nucleus, triggering blood flow to the extremities. That peripheral vasodilation lowers core body temperature by 0.1-0.3C, which is the natural cue for sleep onset and deeper stages. It is the opposite mechanism from melatonin or antihistamines, which depress central nervous system activity and leave you groggy. Glycine works with your sleep architecture, not against your alertness.
The dose, and why it matters
The dose here is not approximate - it is the precise 3g used across Yamadera 2006, Inagawa 2006, and Bannai 2012. Those trials chose 3g because it reliably elevates plasma glycine enough to act at NMDA receptors in the brain's master clock and trigger the core-temperature drop. RCVR uses 3,000mg of free glycine, the literature dose, not a token amount sprinkled in to list it on a label.
How RCVR delivers it
Glycine is also why RCVR can taste good without sugar: glycine is naturally sweet, around 60-70% the sweetness of sugar, so it contributes to a clean taste with zero added sweetener. One can carries the full 3,000mg clinical dose in a drink you actually want to reach for, alongside magnesium and L-theanine that push the same direction.
Clinical Research
Glycine ingestion improves subjective sleep quality in human volunteers
Sleep and Biological Rhythms, 2006
3g glycine before bed improved subjective sleep quality and reduced next-day fatigue in participants with mildly impaired sleep.
View on PubMedNew therapeutic strategy for amino acid medicine: glycine improves the quality of sleep
Journal of Pharmacological Sciences, 2012
Confirmed glycine's mechanism through peripheral vasodilation and core-temperature reduction; 3g consistently improved sleep quality and next-day cognition.
View on PubMedGlycine improves next-day cognitive function after partial sleep restriction
Frontiers in Neurology, 2015
3g glycine before bed improved next-day reaction time and reduced attention lapses after restricted sleep.
View on PubMedRecovery in a can
5 ingredients. Clinical doses. One can.
RCVR delivers clinical doses of taurine, glycine, 300mg magnesium bisglycinate, L-theanine, and Celtic sea salt. $3.50/can. 30-day guarantee.
Frequently Asked Questions
How much glycine should I take for sleep?+
The four sleep RCTs all used 3,000mg (3g) taken before bed. RCVR delivers that exact dose, so you are getting the studied amount, not a fraction of it.
Will glycine make me groggy in the morning?+
No. Glycine works by lowering core body temperature, not by sedating you. Studies actually show improved next-day alertness and cognition, which is the opposite of the melatonin hangover.
Is glycine a sedative?+
No. It is an amino acid that triggers the body's own thermoregulatory sleep signal. It does not depress the central nervous system the way pharmaceutical sleep aids do.