ñ-Pyrrolidinobutiophenone (ñ-PBP) is a stimulant compound developed in the 1960s which has been reported as a novel designer drug. It can be thought of as the homologue lying between the two better known drugs ñ-PPP and ñ-PVP.
In the United States, it is a Schedule I controlled substance.
Sweden's public health agency suggested to classify ñ-PBP as hazardous substance on November 10, 2014.
As of October 2015 ñ-PBP is a controlled substance in China.