Ibogaine and its congeners are sigma 2 receptor-selective ligands with moderate affinity.
European journal of pharmacology June 6, 1995 W D Bowen, B J Vilner, W Williams et al. 95 citations
Ibogaine binds moderately to sigma-2 receptors (Ki = 201 nM) and weakly to sigma-1 receptors (Ki = 8554 nM), showing 43-fold selectivity for sigma-2. Related compounds tabernanthine and ibogamine also bind sigma-2 with similar affinity but have higher sigma-1 affinity, resulting in about 14-fold selectivity. A potential ibogaine metabolite, O-des-methyl-ibogaine, has much weaker sigma-2 affinity (Ki = 5226 nM) and no significant sigma-1 affinity. Coronaridine and harmaline lack significant affinity for either sigma subtype. These findings suggest sigma-2 receptors may contribute to ibogaine's effects.