The increasing global demand for herbal aphrodisiac products has raised concerns regarding their safety and quality due to potential adulteration with synthetic or conventional pharmaceutical active ingredients. This study investigates the presence of sildenafil and tadalafil in selected herbal mixtures marketed for sexual enhancement available in Nigeria, including Mai Sulhu, Mai Rahusa, Mai Sasangi, Jaolin, Saigari Jawaye, and Manisa. A combination of preliminary phytochemical screening, Thin-Layer Chromatography (TLC), and Fourier Transform Infrared Spectroscopy (FTIR) analysis was used to analyze the samples. Phytochemical screening using Dragendorff’s reagent indicated the presence of alkaloids in five of the samples, except Jaolin, suggesting the inclusion of bioactive compounds. TLC analysis revealed that four herbal mixtures had Retention Factor (Rf) values matching those of tadalafil, 0.60 (Mai Salhu and Mai Rahusa), and sildenafil citrate, 0.47 (Saigari yawaye and Manisa), indicating possible adulteration. FTIR spectroscopy further confirmed the presence of these synthetic phosphodiesterase-5 (PDE-5) inhibitors, as spectral peaks in some samples closely correlate with those of sildenafil and tadalafil. The detection of these undeclared pharmaceuticals poses significant health risks, including cardiovascular complications and hazardous drug interactions, as well as potential erectile dysfunction. These findings emphasize the need for stricter regulatory oversight, improved quality control measures, and public awareness regarding the risks associated with adulterated herbal aphrodisiacs. Routine screening using advanced analytical techniques such as High-Performance Liquid Chromatography and Mass Spectrometry is recommended to enhance detection accuracy and precision.