Piperonylic acid is a natural molecule contains in Piper nigrum and bearing a methylenedioxy function that closely mimics the structure of trans-cinnamic acid. Purified piperonylic acid is water-soluble, secure and nontoxic. Recent researchers have verified that piperonylic acid not only inhibited the growth of cancer cells and regulated the immunity, but also improved the lipid metabolism, enhanced endothelial function, and resisted atherosclerotic proliferation. However, related experimental studies are still limited.