Designer drugs in herbal aphrodisiacs.

In the presented case three herbal aphrodisiacs (Libidfit, Satibo and Viamax) were investigated for the presence of regular pharmaceuticals against erectile dysfunction. However, high-performance liquid chromatography with diode array detection and mass spectrometry (HPLC-DAD-MS) and nuclear magnetic resonance (NMR) analyses revealed the presence of ingredients, having a molecular structure strongly resembling those of sildenafil (Viagra) and vardenafil (Levitra). The health risk posed by these analogous substances is high because they were found to be potent phosphodiesterase 5 (PDE5) inhibitors used in pharmacologically relevant quantities having no known safety profile. Based on structural and functional analogy these analogs represent a new class of designer drugs and should be taken off the market for being unapproved drug substances. In the Libidfit court case this was done successfully, setting a precedent.