Dihydroxyphenylglycine

(S)-3,5-Dihydroxyphenylglycine or DHPG is a potent agonist of group I metabotropic glutamate receptors (mGluRs) mGluR1 and mGluR5.

DHPG was the first agonist shown to be selective for group I mGluRs. Agonist activity is found in only the (S)-isomer, and (S)-DHPG may be a partial agonist of group I mGluRs.