Not medical advice

Supplement Hype reports the state of evidence and grades claims. It is not a substitute for a doctor or pharmacist and does not diagnose, treat, or cure anything. Read the full disclaimer →

Head to head

Glycine vs Melatonin

On the strength of human evidence, Melatonin comes out ahead (evidence 55 vs 48). But they're often used for different things — read each claim before deciding.

Shared goals: Sleep

Glycine

Limited

the quiet, cheap sleep amino acid

Marketed
Evidence
Hype ≈ evidence

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 →

Melatonin

Moderate

a timing cue, not a sleeping pill

Marketed
Evidence
Overhyped

Marketing intensity 85 of 100. Evidence strength 55 of 100. Verdict: Overhyped.

A circadian signal that helps you shift when you sleep. It is not a sedative, and most people take far too much.

Full evidence on Melatonin →

Side by side

Metric Glycine Melatonin
Overall tier Limited Moderate
Evidence score 48/100 55/100
Hype score 42/100 85/100
Verdict Hype ≈ evidence Overhyped
Safety concern low moderate

Quick answers

Glycine or Melatonin — which has better evidence?

On the strength of human evidence, Melatonin comes out ahead (evidence 55 vs 48). But they're often used for different things — read each claim before deciding.

Can you take Glycine and Melatonin 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.