3,4-Methylenedioxypropiophenone, also known as 3,4-(Methylenedioxy)phenyl-1-propanone (MDP1P), is a phenylpropanoid found in some plants of the genus Piper and is an isomer of 3,4-methylenedioxyphenyl-2-propanone (MDP2P).

Studies of various chemotypes of Piper marginatum have either detected this compound to be the dominant constituent of the plant's essential oil or absent from it altogether.

[1][2] Of 22 samples collected from South America, specimens from the following regions had the greatest amount of the chemical by dry leaf mass: Manaus (0.35%), Melgaço (0.348%), Belterra (0.33%), Monte Alegre (0.241 to 0.266%), and Alta Floresta (0.123%).

[2] MDP1P is a can be used as a precursor in the synthesis of methylone and various other substituted methylenedioxy- phenethylamine derivatives.

MDP1P is not a scheduled drug at the federal level in the United States nor is it on the DEA list of chemicals.