Potent, selective peptide agonist for the neuropeptide Y Y5 receptor (IC50 values for inhibition of NPY binding to human Y5, Y1, Y2 and Y4 receptors are 0.24, 530, > 500, and 51 nM respectively, Ki at Y5 = 0.1 - 0.15 nM). Stimulates food intake in vivo.

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).

SF-22 is a neuropeptide Y receptor (Y2R) antagonist that crosses the blood-brain barrier and has potential anti-inflammatory activity for the study of diseases associated with neurological disorders.