Salvinorin B methoxymethyl ether (2-O-methoxymethylsalvinorin B) is a semi-synthetic analogue of the natural product salvinorin A used in scientific research.

[1][2] It has a longer duration of action of around 2–3 hours, compared to less than 30 minutes for salvinorin A,[3] and has increased affinity and potency at the κ-opioid receptor.

[4] The crystal structure is almost superimposable with that of salvinorin A.

[5] Structures bound to the κ-opioid receptor have also been reported.

[6] Salvinorin B methoxymethyl ether has a Ki of 0.60 nM at the κ opioid receptor,[7] and is around five times more potent than salvinorin A in animal studies, although it is still only half as potent as its ethoxymethyl ether homolog, 'symmetry'.