Neuropeptide FF receptor agonist (Ki values are 48.4 and 12.1 nM for NPFF1 and NPFF2, respectively). Potentiates the antinociceptive action of morphine in vivo and reverses the loss of morphine potency in tolerant animals. Also increases the amplitude of the sustained current of heterologously expressed acid sensing ion channel 3 (ASIC3) (EC50 ~ 50 μM).

AC-099 hydrochloride is a selective full agonist of the neuropeptide FF2 receptor NPFF2R (EC50=1189 nM) and partial agonist function of the neuropeptide FF1 receptor NPFF1R (EC50=2370 nM) that reverses opioid-induced nociceptive sensitization, and may be used to study neurological.

Potent neuropeptide Y (NPY) Y5 receptor agonist (pEC50 values are 7.82, 6.28, 6.44 and > 6 at rat Y5, Y4, Y1 and Y2 receptors respectively) that displays > 26-fold, > 1000-fold and > 1000-fold selectivity over Y1, Y2 and Y4 receptors respectively. Induces hyperphagia, body weight gain, adiposity, hypercholesterolemia, hyperinsulinemia and hyperleptinemia in vivo. Orally active.