Pentylone (β-Keto-Methyl​benzo​dioxolyl​pentanamine, βk-Methyl-K, βk-MBDP, methyl​enedioxy​pentedrone, or 1‐(3,4‐methylenedioxyphenyl)‐2‐(methylamino)pentan‐1‐one) is a stimulant developed in the 1960s. It is a substituted cathinone (a type of substituted phenethylamine). It has been identified in some samples of powders sold as "NRG-1", along with varying blends of other cathinone derivatives including flephedrone, MDPBP, MDPV and 4-MePPP. It was also found in combination with 4-MePPP being sold as "NRG-3". Reports indicate side effects include feelings of paranoia, agitation and inability to sleep, with effects lasting for several days at high doses.