Glycine

What it does

Glycine is an amino acid involved in collagen structure and nervous system signaling. It is often sold as a sleep-support powder taken before bed.

What the research says

• May improve subjective sleep quality

  Evidence: emerging. Small trials of 3 g before bed suggest benefit; needs larger replication. Needs verification.

• Supports collagen synthesis as a building block

  Evidence: moderate. Glycine is a major component of collagen; the biochemistry is clear, though supplementing to raise collagen is less studied. Needs verification.

DRAFT: small but real sleep signal; the rest is biochemistry plus hope.

What the experts say

Every position links to its source. We include skeptics alongside supporters.

• Andrew Huberman

  “(3-4 nights per week I also take 2g of Glycine and 100mg GABA.)”

  Source, 2021 Takes 2g glycine 3-4 nights per week as part of his sleep routine, alongside 100mg GABA.

• Matthew Walker

  “The other compound that's got some evidence is glycine.”

  Source, 2026-02-10 Tempered view: no supplement is a magic bullet for sleep and pharma would have bottled it by now, but glycine is one of two compounds with some evidence, via lowering the stress response in the wired-but-tired.

Is it worth it?

DRAFT: very cheap with a small real signal; low financial risk even if the effect is modest.