Peptides are provided herein, wherein the peptide bearing one or more amino acid sequence differences relative to SEQ ID NO: 1, with the amino acid sequence differences comprising at least one cysteine replacement or addition.

Peptides are provided herein, wherein the peptide bearing one or more amino acid sequence differences relative to SEQ ID NO: 1, with the amino acid sequence differences comprising at least one cysteine replacement or addition.

The present invention provides oligopeptides, in particular, Ang-(1-7) derivatives, and methods for using and producing the same. In one particular embodiment, oligopeptides of the invention have higher blood-brain barrier penetration and/or in vivo half-life compared to the native Ang-(1-7), thereby allowing oligopeptides of the invention to be used in a wide variety of clinical applications including in treatment of cognitive dysfunction and pain.