amino acid Amino Acids Oral

Glycine

A simple amino acid that acts as an inhibitory neurotransmitter and is a key component of collagen and other structural proteins.

Sci.2-Aminoacetic acid glycine glycine, micronized glycine, powder l-glycine l-glycine hydrochloride l-glycine, micronized l-glycine, powder l-glycine usp micronized glycine glycine powder glycine-alanyl-l-isoleucine Glycine-alanyl-l-isoleucine glycine-alanyl-l-valine glycyl-alanyl-lysine-l-valine Glycine-alanyl-l-valine glycine-alanyl-lysine-l-citrulline glycyl-alanyl-lysine-l-citrulline Glycine-alanyl-lysine-l-citrulline glycine propiony l-carnitine hydrochloride glycine propionyl l-carnitine glycine propionyl-l-carnitine glycine propionyl l carnitine hcl glycine propionyl l-carnitine hcl glycine propionyl-l-carnitine hcl glycine-propionyl-l-carnitine hcl glycine propionyl l-carnitine hydrochloride glycine proprionyl l-carnitine hcl glycocarn glycocarn glycine propionyl l-carnitine hcl glycocarn glycine propionyl-l-carnitine hcl glycocarn glycine propionyl-l-carnitine hydrochloride glycocarn gplc glycocarn-gplc glycocarn (gplc) glycine propionyl-l-carnitine hcl glycocarn(r) glycocarn(r) gplc glycocarn(r) gplc complex glycocarn(tm) gplc Glycine propionyl-l-carnitine glycine-alanyl-l-lysine Glycine-alanyl-l-lysine glycine-alanyl-l-methionine Glycine-alanyl-l-methionine glycine-alanyl-l-threonine Glycine-alanyl-l-threonine glycine-alanyl-l-tryptophan Glycine-alanyl-l-tryptophan glycine-alanyl-lysine-l-glutamine Glycine-alanyl-lysine-l-glutamine glycine-alanyl-l-leucine glycyl-alanyl-lysine-l-isoleucine glycyl-alanyl-lysine-l-leucine Glycine-alanyl-l-leucine glycine-alanyl-l histidine Glycine-alanyl-l-histidine glycine-alanyl-l-phenylalanine Glycine-alanyl-l-phenylalanine glycine-l-arginine-alpha-ketoisocaproic acid Glycine-Arginine alpha-ketoisocaproate
16 forms
Oral

About Glycine

Glycine is the simplest and a non-essential amino acid, serving as a fundamental building block for proteins. It functions as an inhibitory neurotransmitter in the central nervous system, a precursor for glutathione and creatine synthesis, and a key component in the structure of collagen, elastin, and gelatin. It is involved in metabolic processes, bile acid conjugation, and detoxification.

Official resources

Fact sheets from the NIH Office of Dietary Supplements related to this ingredient group.

Dietary Supplement Label Database

Ingredient group data in NutriNav is aligned with the NIH Dietary Supplement Label Database (DSLD).

DSLD group id
92

At a glance

Suggested daily

No formal RDA. Estimated endogenous synthesis and dietary intake total ~10 grams per day for adults. Supplemental doses in studies typically range from 1 to 15 grams daily.

Max safe daily

No established UL. Doses up to 60 grams daily have been used in studies with minimal adverse effects, though gastrointestinal discomfort may occur at high intakes.

Approval status

supplement

Compare All Forms

16 forms

Compare supplement forms of Glycine by absorption quality and what your body actually gets from each:

High Moderate Low
Form Absorption Steps to absorb Notes Action
Glycine
  • CAS: 56-40-6
  • Label category: synthetic
 — — — View →
Glycine (Free Form)
  • CAS: 56-40-6
 — — — View →
Glycine propionyl-l-carnitine — — — View →
Glycine-alanyl-l-histidine — — — View →
Glycine-alanyl-l-isoleucine — — — View →
Glycine-alanyl-l-leucine — — — View →
Glycine-alanyl-l-lysine — — — View →
Glycine-alanyl-l-methionine — — — View →
Glycine-alanyl-l-phenylalanine — — — View →
Glycine-alanyl-l-threonine — — — View →
Glycine-alanyl-l-tryptophan — — — View →
Glycine-alanyl-l-valine — — — View →
Glycine-alanyl-lysine-l-citrulline — — — View →
Glycine-alanyl-lysine-l-glutamine — — — View →
Glycine-Arginine alpha-ketoisocaproate — — — View →
Micronized Glycine
  • CAS: 56-40-6
 — — — View →

Also appears on labels as

Additional names seen on supplement labels for forms of this ingredient (beyond the main aliases above).

2-Aminoacetic acid, Gly

Type: Amino Acids

Building blocks of proteins. Essential amino acids must be obtained from diet, while non-essential can be synthesized by the body.

Absorption: Amino acids are generally well-absorbed. Some forms (like citrulline) are more effective than others (like arginine).

Interactions: Generally safe but high doses can cause digestive issues. Some amino acids can affect neurotransmitter levels.

Watch out for

Possible interactions or cautions — talk to a healthcare provider if unsure.

  • May potentiate effects of CNS depressants (e.g., benzodiazepines, alcohol) due to its inhibitory neurotransmitter activity.
  • Theorized to interact with clozapine, but clinical significance is unclear.

Potential Benefits

Benefits associated with Glycine forms:

Sleep Quality Joint Health Supports collagen synthesis Improves sleep quality Supports Muscle Growth Muscle Recovery

And 1 more benefit...

Potential Side Effects

Side effects associated with Glycine forms:

Drowsiness How serious: Mild Gastrointestinal Discomfort How serious: low Gastrointestinal Distress How serious: low

What does the research say?

Glycine has been studied for its role in protein synthesis, neurotransmission, and metabolic processes. Research indicates potential benefits in sleep quality, muscle mass preservation, and metabolic health.