σ1 Receptor/μ Opioid receptor modulator 1 (Compound 44) is a potent σ1 receptor antagonist and μ opioid receptor agonist with K i s of 1.86 nM and 2.1 nM, respectively.σ1 Receptor/μ Opioid receptor modulator 1 exhibits potent analgesic activity. σ1 Receptor/μ Opioid receptor modulator 1 can be used for the research of neuropathic pain.