 However, 3-MMC has still appeared on the recreational drug market as an alternative to mephedrone, and was first identified being sold in Sweden in 2012.Unlike other legal highs 3-MMC was tested and characterized in large mammals, providing much more knowledge about it than is known about other synthetic cathinones.3-MMC is a monoamine transporter substrate that potently inhibits norepinephrine uptake and displays more pronounced dopaminergic "vs." serotonergic activity.