As part of an ongoing investigation for discovery of naturally occurring anti-obesity agents from medicinal plants, a porcine pancreatic lipase assay was used in an initial screening procedure; according to the results, an EtOAc-soluble portion of Galla Rhois extract exhibited significant inhibitory activity, with an IC50 value of 6.4 ± 0.7 μg/mL. The gene discussed is PNLIP; the disease is obesity due to melanocortin 4 receptor deficiency.