Head to head
GABA vs Glycine
On the strength of human evidence, Glycine comes out ahead (evidence 48 vs 35). But they're often used for different things — read each claim before deciding.
GABA
Limitedcalm in a capsule — if it reaches your brain
Marketing intensity 70 of 100. Evidence strength 35 of 100. Verdict: Overhyped.
Sold as instant calm, but the catch is basic biology: oral GABA struggles to cross into the brain. A few small trials hint at a sleep effect anyway, by unclear means.
Full evidence on GABA →Glycine
Limitedthe quiet, cheap sleep amino acid
Marketing intensity 42 of 100. Evidence strength 48 of 100. Verdict: Hype ≈ evidence.
Under-marketed and reasonably promising for sleep. The longevity buzz, though, is built almost entirely on worms and mice.
Full evidence on Glycine →Side by side
| Metric | GABA | Glycine |
|---|---|---|
| Overall tier | Limited | Limited |
| Evidence score | 35/100 | 48/100 |
| Hype score | 70/100 | 42/100 |
| Verdict | Overhyped | Hype ≈ evidence |
| Safety concern | low | low |
Quick answers
GABA or Glycine — which has better evidence?
On the strength of human evidence, Glycine comes out ahead (evidence 48 vs 35). But they're often used for different things — read each claim before deciding.
Can you take GABA and Glycine together?
This page compares the evidence, not interactions. Some supplements interact with each other or with medications — check each one's safety section and talk to a pharmacist before stacking.