GABA vs Glycine: Two Ways to Slow Down

GABA and Glycine are the two main "stop" signals in your central nervous system (CNS).

Glutamate is the "gas." GABA and Glycine are the "brakes." Supplementing them helps if your brakes are worn out.

Feature	GABA	Glycine
Mechanism	Brain Inhibition	Brain Stem / Temp Regulation
Primary Effect	Relaxation	Deep Sleep & Cooling
Bioavailability	Poor (Hard to cross BBB)	Good
Taste	Sour / Bitter	Sweet

Mechanisms: Brain vs Brain Stem

GABA: The Master Switch

GABA is the primary inhibitory neurotransmitter in the brain. It counteracts anxiety and over-stimulation.

However, swallowed GABA has difficulty reaching the brain. It often works by relaxing the *body* (peripheral nerves in the gut), which sends a signal back to the brain to chill out.

Glycine: The Thermostat

Glycine works primarily in the brain stem and spinal cord. It paralyzes muscles during REM sleep (so you don't act out your dreams).

Crucially, it also lowers core body temperature by dilating blood vessels in the extremities. This temperature drop is the biological trigger for sleep onset.

What it means

GABA tries to turn off the mind's thoughts. Glycine tries to turn off the body's movement and heat.

Which One Matches Your Goal?

For Staying Asleep

Winner: Glycine.

Glycine improves "sleep architecture." You get more Deep Sleep and REM sleep, waking up feeling biologically more rested.

For Pre-Sleep Anxiety

Winner: GABA.

If you can't fall asleep because you are tense or worried, GABA (or a GABA-booster like Lemon Balm) is more appropriate than Glycine.

The Verdict

Choose GABA if: You are mentally wired and physically tense.

Choose Glycine if: You want better sleep quality, detox support, or a sugar-free sweetener for your tea.