We reported the case of two young men, known to be polydrug abusers, arrested in possession of plastic bags of crystals and capsules (total about 300 grams) suspected to be narcotics or new psychoactive substances (NPS). Placed in custody, they will quickly hospitalize for their bad condition (tachycardia, dysarthria, great excitement) where blood samples are taken. Hair samples will be taken for the two subjects, respectively, 1 month and 4 months after hospitalization. Analyses of seized materials, blood and hair samples were requested by the justice and sent to the laboratory for identification and document the drug exposure. Identification of seized materials was performed with gas chromatography-mass spectrometry (GC-MS) using commercial and free specialized mass spectra libraries. Blood toxicological analysis was performed by gas chromatography with flame ionization detection (GC-FID), high performance liquid chromatography-diode array detection (HPLC-DAD), gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-mass spectrometry (LC-MS/MS). Several hair segments were analyzed by LC-MS/MS. Alpha-pyrrolidinopentiophenone or alpha-pyrrolidinovalerophenone (α-PVP, also known as street name “flakka”) and pyrrolidinoheptiophenone (PV8, also known as α-PHpP or α-PEP) were identified in seized materials. Toxicological analysis in peripheral blood revealed the presence of α-PVP (100 and 70ng/mL, respectively), 2-oxo-PVP (50.4 and 22.7ng/mL, respectively), PV8, diazepam and metabolites for the two subjects. Hair analysis demonstrated the presence of α-PVP (0.88 and 0.19 to 1.99ng/mg, respectively), 2-oxo-PVP, morphine, cocaine and metabolites, amphetamine, MDMA, methadone and EDDP and suggested a repeated consumption of these substances.