Glycine
Glycine is the simplest amino acid. The body can make it itself, and it is abundant in collagen and other protein-rich foods.
Also listed as 2-Aminoacetic acid, L-Glycine
Does a studied dose establish a safe upper limit?
VKM assessed specified supplemental amounts up to 650 mg daily as unlikely to cause harm in adults. That conclusion does not assess the 3 g sleep regimen. The agency also found no human studies specifically designed to establish adverse-effect thresholds. 1
A specific concern with clozapine
Two small trials added high-dose glycine to clozapine treatment for schizophrenia. Neither found a useful symptom benefit; one raised concern about possible interference, while the other reported no clinical worsening. These preliminary, differing findings warrant review with the prescribing clinician rather than an unsupervised combination. 2 3
Who was left out of the research?
The GlyNAC trial excluded pregnancy and serious conditions. Its tolerability findings cannot establish safety in those groups. 4
For information, not individual medical advice. Ingredient studies do not establish the effectiveness of these products.