1-(-1-Naphthyl)piperazine (1-NP) is a drug which is a phenylpiperazine derivative. It acts as a non-selective, mixed serotonergic agent, exerting partial agonism at the 5-HT1A, 5-HT1B, 5-HT1D, 5-HT1E, and 5-HT1F receptors, while antagonizing the 5-HT2A, 5-HT2B, and 5-HT2C receptors.