data + articles · 1 listed
newest 2014spec sheet12 rows
Methylphenylpiracetam (MPP) is a methylated analogue of phenylpiracetam developed at the Latvian Institute of Organic Synthesis, and its most studied stereoisomer, E1R, is a positive allosteric modulator of the sigma-1 receptor [1]. In mice, E1R enhances memory retention and reverses scopolamine-induced cognitive impairment without altering locomotor activity, effects abolished by the selective sigma-1 antagonist NE-100 [1]. Unlike its parent phenylpiracetam, which is primarily a dopaminergic psychostimulant, MPP is characterized as a non-stimulant cognition enhancer acting through sigma-1 chaperone signaling [1].
- Enhances memory retention in preclinical models
- Reverses scopolamine-induced cognitive impairment
- Non-stimulant profile with no locomotor activation
- Acts through sigma-1 signaling relevant to neuroprotection
- Potential for interaction with other sigma-1-active drugs is unstudied.
- As a racetam it may in theory increase cholinergic demand and cause headache.
Overview
Methylphenylpiracetam is a 4,5-disubstituted derivative of piracetam, differing from phenylpiracetam by an added methyl group on the 2-oxopyrrolidine ring. Because the molecule carries multiple chiral centers, it exists as several stereoisomers, and pharmacological interest has focused on the (4R,5S) isomer designated E1R, which shows the strongest positive allosteric modulation of the sigma-1 receptor [1].
In behavioral pharmacology, E1R facilitates passive-avoidance retention in a dose-related manner and alleviates scopolamine-induced deficits in passive-avoidance and Y-maze tasks in mice, indicating activity against cholinergic dysfunction [1]. Crucially, these effects occur without changes in open-field locomotion, distinguishing MPP from the stimulant profile of racemic phenylpiracetam, and the reported cognition-enhancing potency of E1R exceeds that of R-phenylpiracetam [1]. The sigma-1 dependence of the effect is demonstrated by its blockade with the selective antagonist NE-100 [1].
The compound remains an experimental, preclinical molecule with no approved human use. It is supplied as a research powder and is best understood as a probe for sigma-1 receptor pharmacology rather than a validated nootropic.
- Adding a single methyl group to phenylpiracetam shifts its pharmacology away from dopamine-driven stimulation toward sigma-1 receptor modulation, giving a non-stimulant memory effect [1].
- In head-to-head preclinical comparison, the E1R isomer of methylphenylpiracetam was reported to enhance cognition more strongly than R-phenylpiracetam itself [1].
Mechanism
The sigma-1 receptor is an endoplasmic-reticulum chaperone protein that regulates intracellular calcium signaling and is implicated in learning, memory and neuroprotection. E1R, the active stereoisomer of methylphenylpiracetam, acts as a positive modulator of this receptor: it potentiates the response to the selective sigma-1 PRE-084 in electrically stimulated rat vas deferens and amplifies bradykinin-induced increases in intracellular calcium, effects that are blocked by the sigma-1 NE-100 [1].
By sensitizing sigma-1 signaling rather than directly agonizing a monoamine transporter, MPP enhances cholinergically dependent memory processes while leaving locomotor and stimulant pathways largely untouched [1]. This mechanism separates it conceptually from phenylpiracetam and from its -transporter-targeting relative R-phenylpiracetam, and positions it within the growing class of sigma-1 modulators explored for cognitive and neurodegenerative indications.
receptor fingerprint
Sigma-1 receptorPositively modulates
Scopolamine-induced amnesiaReverses
Locomotor activityNo effect
Dosingtypical ranges, not medical advice
interested in protocols and clinical dosages? make an account to see them! ^_^
Safetyrisks and cautions, not medical advice
There is essentially no human safety data for methylphenylpiracetam; everything known comes from rodent pharmacology, where E1R was well tolerated and did not produce the locomotor stimulation seen with amphetamine-like drugs. That means real-world side effects, interactions and long-term risks are unknown. Because it modulates sigma-1 signaling, it could in principle interact with other sigma-active drugs, and its racetam backbone suggests the usual mild possibilities of headache from cholinergic demand. It is strictly a research chemical, not an approved supplement or medicine, and should be treated as research-use-only with no established safe human dose.
History
Methylphenylpiracetam and its lead stereoisomer E1R were designed and characterized by scientists at the Latvian Institute of Organic Synthesis in Riga, the same institution associated with phenylpiracetam and mildronate, with the defining pharmacology published by Zvejniece, Dambrova and colleagues in 2014 [1]. It grew out of structure-activity work aimed at improving on the phenylpiracetam scaffold by shifting activity from dopaminergic stimulation toward sigma-1 modulation.
Reputation
Among researchers, MPP and E1R are viewed as a clean and interesting example of sigma-1 positive allosteric modulation with genuine, if preclinical, cognition-enhancing data behind them [1]. In the nootropic community the compound is niche and often confused with phenylpiracetam; enthusiasts are intrigued by the non-stimulant memory angle, but everyone honest about it acknowledges there are no human trials and the hype outruns the evidence.
Subjective profileweighing the evidence above
Nothing has been tested in people, so there is nothing to recommend. The sigma-1 memory work on the E1R isomer is genuinely interesting mouse pharmacology and that is where it ends; human safety is entirely unknown. Phenylpiracetam is the version with actual human use behind it.
Resources
This entry is here for reference.
Research
- 1.The cognition-enhancing activity of E1R, a novel positive allosteric modulator of sigma-1 receptors.
1 listed here; entry last updated August 2026
Reviews
My notesprivate to this device
FAQ
How is MPP different from phenylpiracetam?
Phenylpiracetam is chiefly a dopaminergic stimulant, whereas methylphenylpiracetam adds a methyl group and works as a sigma-1 receptor positive allosteric modulator with a non-stimulant memory effect.
What is E1R?
E1R is the (4R,5S) stereoisomer of methylphenylpiracetam and is the form responsible for the strongest sigma-1 modulation and cognitive effects in animal studies.
Has it been tested in humans?
No. All of the published data are from rodent experiments, so there is no established human dose, benefit or safety profile.
Who developed it?
It was developed and characterized at the Latvian Institute of Organic Synthesis, the same institute linked to phenylpiracetam.
Limitations of the evidence
- No human side-effect data exist; safety is entirely unknown.
Adverse effects
- Potential for interaction with other sigma-1-active drugs is unstudied.
- As a racetam it may in theory increase cholinergic demand and cause headache.
Notes and cautions
- Long-term effects have never been evaluated in any species over extended use.