Provided herein are compositions and formulations comprising S-adenosyl-L-methionine (“SAM-e” or “SAMe”) and one or more gallic acid esters. Also provided herein are methods for improving the delivery of SAMe. Compositions and formulations provided herein increase SAMe plasma concentrations and area under the curve (AUC) values. Also provided herein are methods of treating a disease or disorder in a subject by administering compositions or formulations comprising exogenous SAMe and one or more gallic acid esters.