The present invention provides an asymmetrically substituted diketopiperazine having the general structure of:wherein R is H or an alkyl group of 1-10 carbons n or m = 0 -20 X is an amide, ester, sulfone, sulfoxide, amine, or ketone and Y is an amide, ester, acid, hydroxyl, phenol, sulfoxide, phosphoric acid, or thiol, for use as a drug delivery system in the delivery of active agents. Further preferred uses include regulating blood glucose levels, reducing or lowering fasting blood glucose levels, and treating diabetes, such as type II diabetes.
