Substance P-related peptide that inhibits binding of G proteins to their receptors. Competitively and reversibly inhibits M2 muscarinic receptor activation of Gi or Go and inhibits Gs activation by β-adrenoceptors.

GSK-25 maintains good selectivity against a panel of 31 kinases, as well as RSK1 and p70S6K (RSK1 IC50 of 398 nM, p70S6K IC50 of 1000nM), and a dramatically improved P450 profile (>2.2 uM at all isozymes tested).

1-Dehydro-6-gingerdione is a 5-HT1A receptor partial agonist.