Methylphenylpiracetam is a derivative of piracetam and a positive allosteric modulator of the sigma-1 receptor.

[2] E1R is the (4R,5S) stereoisomer of methylphenylpiracetam that has been shown to have the greatest effect on the modulation of the sigma-1 receptor.

[1][3] E1R enhances cognition and has efficacy against cholinergic dysfunction in mice without affecting locomotor activity.

[2] Pretreatment with E1R enhanced the σ1R agonist PRE-084's stimulating effect and facilitated passive avoidance retention.

[2] Methylphenylpiracetam is a schedule 4 substance in Australia under the Poisons Standard (February 2020).