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Clinical data
Routes of
ATC code
  • none
Legal status
Legal status
  • In general: unscheduled
  • Methyl 3-[2-[benzyl(methyl)amino]ethyl]benzoate
CAS Number
PubChem CID
Chemical and physical data
Molar mass283.371 g·mol−1
3D model (JSmol)
  • CN(CCc1cccc(c1)C(=O)OC)Cc2ccccc2
  • InChI=1S/C18H21NO2/c1-19(14-16-7-4-3-5-8-16)12-11-15-9-6-10-17(13-15)18(20)21-2/h3-10,13H,11-12,14H2,1-2H3

PRL-8-53 is a nootropic research chemical derived from benzoic acid and phenylmethylamine (Benzylamine) that has been shown to act as a hypermnesic drug in humans; it was first synthesized by medical chemistry professor Nikolaus Hansl at Creighton University in the 1970s as part of his work on amino ethyl meta benzoic acid esters.[1][2]

Nootropic effects[edit]

PRL-8-53 is not a medical treatment for disease or illness, although a nootropic effect in healthy individuals has been claimed. A single study in humans was reported in 1978. The double-blind trial of PRL-8-53 in 47 healthy volunteers measured its effects on a variety of cognitive measures. 5 mg of the drug was administered orally 2–2.5 hours before the study tasks.[1] Overall improvements in recollection differed based on how many words were recalled under placebo, with the poor performers (six words or fewer) experiencing an 87.5-105% increase in recollection and the high performers (eight or more words) a 7.9-14% increase which failed to reach statistical significance; when controlling for subjects over the age of 30 only, a 108-152% increase was noted. The researchers noted that this was likely a result of a ceiling effect due to many of their subjects scoring close to 100% on the recall test even on placebo.[1] No side effects were reported during the trial.[1]

Mechanism of action[edit]

The exact mechanism of action of PRL-8-53 remains unknown. Doses up to 200 mg/kg are not observed to have stimulant properties, and a dosage of 20 mg/kg does not potentiate the effects of dextroamphetamine in rats.[1] It displays possible cholinergic properties, and potentiates dopamine while partially inhibiting serotonin. PRL-8-53 reverses the catatonic and ptotic effects of reserpine.[1][3]


PRL-8-53 is relatively non-toxic, with an oral LD50 in mice of 860 mg/kg, giving the drug a high therapeutic index. Doses above 8 mg/kg have brief hypotensive effects in canines. High doses depress motor activity in the rat and mouse, with the ED50 for a 50% reduction in motor activity of mice at 160 mg/kg. PRL-8-53 displays spasmolytic effects.[3]


Methyl 3-(2-(benzylmethylamino)ethyl)benzoate hydrochloride
3-(2-benzylmethylaminoethyl) benzoic acid methyl ester hydrochloride
3-(2-(Methyl(phenylmethyl)amino)ethyl)benzoic acid methyl ester hydrochloride

See also[edit]


  1. ^ a b c d e f Hansl NR, Mead BT (April 1978). "PRL-8-53: enhanced learning and subsequent retention in humans as a result of low oral doses of new psychotropic agent". Psychopharmacology. 56 (3): 249–53. doi:10.1007/BF00432846. PMID 418433. S2CID 21036209.
  2. ^ US Patent 3870715 A: Substituted amino ethyl meta benzoic acid esters
  3. ^ a b Hansl NR (March 1974). "A novel spasmolytic and CNS active agent: 3-(2-benzylmethylamino ethyl) benzoic acid methyl ester hydrochloride". Experientia. 30 (3): 271–2. doi:10.1007/BF01934822. PMID 4824605. S2CID 918343.