<p>Hair loss is a disorder that occurs regardless of sex and affects both the patient’s appearance and quality of life. Rather than visiting a doctor for treatment, many patients prefer to use consumer health products, such as cosmetics (hair loss tonic or ampoules) or dietary supplements. To date, medicines such as minoxidil, finasteride, and flutamide have been successfully employed as treatments for hair loss, while prostaglandin F_2α analogs have been proposed as alternative treatments for hair loss. Nevertheless, these compounds can cause various adverse reactions, and the illegal adulteration of the corresponding products has also been reported. Consequently, significant caution is required when employing such treatments. In this study, high-performance liquid chromatography and ultra-performance liquid chromatography combined with tandem mass spectrometry were used to simultaneously analyze 17 hair growth compounds (bimatoprost free acid, bimatoprost isopropyl ester, bimatoprost serinol amide, cyclopropylmethylbimatoprost, cyproterone acetate, dechloro ethylcloprostenolamide, dutasteride, estradiol, finasteride, flutamide, 15-ketobimatoprost, latanoprost, methyltestosterone, minoxidil, spironolactone, testosterone propionate, and triaminodil). The developed method was validated in accordance with the International Conference on Harmonization guidelines to evaluate its specificity, limits of detection and quantification, linearity, recovery, precision, and accuracy. Finally, the developed method was applied in the analysis of specific products. The established method therefore enables the reliable detection of illicit hair growth compounds, supporting both regulatory compliance and consumer safety.</p>