4-Methylmethamphetamine (4-MMA), also known as mephedrine, is a putative stimulant and entactogen drug of the amphetamine family.

[3][4] 4-MMA acts as a potent and well-balanced serotonin–norepinephrine–dopamine releasing agent (SNDRA).

[1][2] It induces hyperlocomotion and stereotypy (psychostimulant-like effects) as well as hyperthermia in mice, similarly to methcathinone.

[5][6] In contrast to methamphetamine and methcathinone, 4-MMA appears to produce minimal dopaminergic neurotoxicity in mice.

[5][6] Accordingly, the dopaminergic neurotoxicity of 4-MMA was greatly enhanced by the dopamine precursor levodopa (L-DOPA), the monoamine oxidase inhibitor (MAOI) pargyline, and methamphetamine (a VMAT2 inhibitor/reverser), all of which are known to increase the cytosolic pool of dopamine.