Glycine
Sarcosine
N-Methylglycine
Monomethylglycine
Methylamino-Acetic Acid

Unexplored Excipients in Biotherapeutic Formulations: Natural Osmolytes as Potential Stabilizers Against Thermally Induced Aggregation of IgG1 Biotherapeutics

https://link.springer.com/article/10.1208/s12249-021-02183-8

results rank the osmolytes’ stabilizing trend to be sarcosine > betaine > hydroxyectoine > ectoine. Sarcosine emerged as the most successful osmolyte rendering highest degree of protection against aggregation.

The glycine transport inhibitor sarcosine is an NMDA receptor co-agonist that differs from glycine

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2727032/

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Glycerol
Glycine
Sarcosine
Betaine
Proline
Choline
Taurine
Sorbitol
Inositol