PRL-8-53 is a benzoic acid ester with a benzylmethylamino side chain, developed by Nikolaus Hansl and first described in 1974 in animal studies.
Amounts reported for PRL-8-53 are listed under Reported protocols, each with its source and study kind. No amount ladder is inferred from them. This is educational source context, not a protocol or recommendation.
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Human study rows are described per source under Reported protocols; they belong to their trial populations and are not a general amount.
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What published studies and recent community write-ups report about amounts, timing and course length. 1 clinical, 1 preclinical and 3 community-reported rows, each linked to its source. These are descriptions of what others report, not instructions, and nothing here is medical advice.
| Context | Dose | Frequency | Route | Course | Source |
|---|---|---|---|---|---|
| Clinical1 row | |||||
| The only human study: verbal learning and retention47 healthy adult volunteers recruited from university faculty and students | 5 mg single oral dose | Single dose, taken 2-2.5 hours before testing | Oral capsule | Single dose per test session, with recall checked 24 hours and 4 days laterNot applicable | Psychopharmacology (PubMed)1978 |
| Under double-blind conditions, acquisition of 12-word lists improved slightly and retention improved significantly (most p values below 0.01), with the largest gains in people with poor baseline recall and those over 30; visual reaction time and hand steadiness did not change. The indexed abstract says only 'low oral doses', and the 5 mg amount and 47 subjects come from the paper's methods section. A note added in proof records that the batch used contained a small amount of a desmethyl impurity. The study was never replicated. | |||||
| Preclinical1 row | |||||
| Animal pharmacology summarised in the 1978 paperMice, rats and dogs, as reported in the introduction of the human study and in Hansl's 1974 note | Oral LD50 of 860 mg/kg in mice; 160 mg/kg halved mouse motor activity; 20 mg/kg did not potentiate d-amphetamine in rats; no stereotypy up to 200 mg/kg; up to 8 mg/kg left dog blood pressure unchanged | Single doses | Oral and systemic | AcuteNot applicable | Psychopharmacology (PubMed)1978 |
| The authors describe a cholinergic response, potentiation of dopamine and partial inhibition of serotonin in animals, reversal of reserpine-induced catatonia, and low toxicity. These figures appear in the introduction of the 1978 human paper, which cites Hansl's own 1973-1974 reports; the 1974 Experientia note is indexed without an abstract, and no modern study has repeated any of it. | |||||
| Community-reported3 rows | |||||
| Vendor-neutral research profile with certificate data | Not stated; the page reports 96.8 percent average tested purity across 3 certificates and says no validated human dosing regimen exists | Not stated | Oral (hydrochloride salt as sold) | Not statedNot stated | Community resource2026 |
| This 2026 profile aggregates three certificates of analysis from two laboratories, averaging 96.8 percent purity, and states that widely circulated claims about specific neurotransmitter effects are unsupported marketing. It lists the absence of toxicology, interaction and dose-ranging data as the central caution. It is a database page about the research-chemical market, not a dosing guide. | |||||
| Community compound page on the evidence gap | No dose given; the page says the hydrochloride has a molecular weight of 319.83 g/mol and the free base 283.4 g/mol | Not stated | Oral | Not statedNot stated | Community resource2026 |
| Reviewed in September 2026, this page stresses that PubMed holds exactly one record for PRL-8-53, that no pharmacokinetic, repeat-dose, toxicology or registered-trial data exist, and that the often repeated claim of doubled memory comes from secondary retellings of subgroup results. It explicitly declines to give a dose. | |||||
| Vendor research-use listing | 10 mg per capsule, 60 capsules per bottle | Not stated (sold for laboratory research only) | Oral capsule format | Not statedNot stated | Community resource2026 |
| Vendor claim. The vendor sells PRL-8-53 as 10 mg capsules, twice the amount used in the 1978 study, with a third-party LC-MS report for lot PR01 that records appearance only and no purity verdict. The page cites the 1978 paper, gives no dosing information and states the product is not for human consumption. | |||||
Plus 3 community resources (dosing guides, forum threads and vendor write-ups), reported above but not linked.
PRL-8-53 is a benzoic acid ester with a benzylmethylamino side chain, developed by Nikolaus Hansl and first described in 1974 in animal studies. That note presented it as a spasmolytic and centrally active agent, and its entire human record is a single 1978 double-blind study in which 47 healthy volunteers took one 5 mg capsule and showed better recall of word lists a day and four days later; nothing has been published on it since, in people or animals. It is sold as the hydrochloride salt by research-chemical vendors and has never entered formal drug development or been approved anywhere.
These themes describe recurring questions in published research. They are not claims of effectiveness or recommendations for use.
Neuroplasticity, cognition, stress and sleep models.
Under double-blind conditions, acquisition of 12-word lists improved slightly and retention improved significantly (most p values below 0.01), with the largest gains in people with poor baseline recall and those over.
The authors describe a cholinergic response, potentiation of dopamine and partial inhibition of serotonin in animals, reversal of reserpine-induced catatonia, and low toxicity. These figures appear in the introduction.
This 2026 profile aggregates three certificates of analysis from two laboratories, averaging 96.8 percent purity, and states that widely circulated claims about specific neurotransmitter effects are unsupported.
Reviewed in September 2026, this page stresses that PubMed holds exactly one record for PRL-8-53, that no pharmacokinetic, repeat-dose, toxicology or registered-trial data exist, and that the often repeated claim of.
Vendor claim. The vendor sells PRL-8-53 as 10 mg capsules, twice the amount used in the 1978 study, with a third-party LC-MS report for lot PR01 that records appearance only and no purity verdict. The page cites the.
Study models remain visible so laboratory and animal findings are not mistaken for established human outcomes.
1 protocol row on this page come from human trials, trial registrations, regulator labels or reviews of human data. Approval status and populations are stated per row.
1 protocol row describe animal, cell or toxicology work. Amounts from these rows do not translate to people.
3 rows record what blogs, vendor write-ups or forums describe for PRL-8-53. None has been verified against primary literature.
Sequence, synonyms and registry identifiers as recorded in PubChem, the National Library of Medicine's open chemistry database. Formula, mass and CAS number are summarized at the top of the page.
PRL-8-53 (hydrochloride), PRL 8-53, Methyl 3-(2-(benzyl(methyl)amino)ethyl)benzoate hydrochloride, Benzoic acid, 3-(2-(methyl(phenylmethyl)amino)ethyl)-, methyl ester, hydrochloride, UNII 2P77XL8HV7, HY-13976A
HLBBSWSJLPLPRU-UHFFFAOYSA-N
methyl 3-[2-[benzyl(methyl)amino]ethyl]benzoate;hydrochloride
3 curated references, each with its journal, year and study model, plus 3 community resources reported but not linked.