Physical effects: Increased libido On the 3-MMC page this effect is cathegorised as a Physical effect. On the Mephedrone page it is classified as a Cognitive effect. It sounds like the 3-MMC's page describes this effect more precisely but this is open to discussion. Moreover, I have not used 4-MMC so I can't attest whether the quality of the libido stimulation is markedly different, cause it would make sense if the lust is more mind-present than bodily, if that makes sense. If there is no difference there, I will move this effect to the physical effects.
Yeah I can attest to 4-MMC being more lusty, 3-MMC affects libido as more physically horny than deeply arousing