2C-MMDA-2 (2C-2), also known as MMDPEA-2 or 6-methoxy-MDPEA, as well as 2-methoxy-4,5-methylenedioxyphenethylamine, is a serotonin 5-HT₂ receptor agonist of the phenethylamine and methylenedioxyphenethylamine families. Along with lophophine (2C-MMDA-1 or MMDPEA-1), it is one of the positional isomers of methoxymethylenedioxyphenethylamine (MMDPEA). 2C-MMDA-2 is also the phenethylamine analogue of MMDA-2.

In his book PiHKAL (Phenethylamines I Have Known and Loved), Alexander Shulgin described testing 2C-MMDA-2 at doses of up to 2.6 mg and observed no effects but did not try higher doses.

2C-MMDA-2 is a full agonist of the serotonin 5-HT_2A, 5-HT_2B, and 5-HT_2C receptors. Its EC₅₀Tooltip half-maximal effective concentration (E_maxTooltip maximal efficacy) values were 148 nM (102%) for G_q signaling and 589 nM (107%) for β-arrestin2 signaling at the serotonin 5-HT_2A receptor, 204 nM (104%) at the serotonin 5-HT_2B receptor, and 9.77 nM (109%) at the serotonin 5-HT_2C receptor. 2C-MMDA-2 was more potent as a serotonin 5-HT₂ receptor agonist than mescaline.

The NBOMe derivative of 2C-MMDA-2 is 2C2-NBOMe. It is a highly potent serotonin 5-HT₂ receptor agonist and produces the head-twitch response, a behavioral proxy of psychedelic effects, in rodents.

Alexander Shulgin in tested 2C-MMDA-2 in 1963. He described these findings in his 1991 book PiHKAL (Phenethylamines I Have Known and Loved), which is when 2C-MMDA-2 appears to have been first described in the literature. Later, 2C-MMDA-2 was assessed in terms of serotonin receptor activity by Jason Wallach and colleagues in 2023.