Glycine (unmodified free amino acid)
Glycine (unmodified free amino acid) is a tier 1 form of Glycine, used in 1,573 on-market products .
1,573
on-market products
tier 1
quality tier
n/a
elemental fraction
Why this tier: The form used in essentially all clinical glycine literature; glycine is the only proteinogenic amino acid with no stereocenter, so "L-Glycine" is a labeling convention/synonym, not a distinct or superior form.
Source: Bannai M et al. 2012, Front Neurol 3:61, PMID 22529837