The parent compound from which BU-48 was derived (with N-methyl rather than methylcyclopropyl on the nitrogen and lacking the aliphatic hydroxyl group) is a powerful μ-opioid agonist 1000x more potent than morphine, but in contrast BU-48 has only weak analgesic effects and instead acts primarily as a δ-opioidagonist. Its main effects are to produce convulsions, but it may also have antidepressant effects.
^Broom DC, Guo L, Coop A, Husbands SM, Lewis JW, Woods JH, Traynor JR (September 2000). "BU48: a novel buprenorphine analog that exhibits delta-opioid-mediated convulsions but not delta-opioid-mediated antinociception in mice". The Journal of Pharmacology and Experimental Therapeutics. 294 (3): 1195–200. PMID10945877.