Dopaminergic

9-Me-BC is a β-carboline — the same tryptophan-derived ring system found in cooked meat, coffee and tobacco smoke, and in human blood and brain. Most members of that family damage dopaminergic neurons, which is why they have been investigated as causes of Parkinson's disease; 9-Me-BC does the opposite in cell culture and in one rat study, raising tyrosine hydroxylase, inducing neurotrophic factors and restoring dopamine after a neurotoxin. Ten days of treatment also improved maze learning in rats and thickened dendrites in the dentate gyrus. No human has been studied at any dose.

Adderall contains mixed amphetamine salts, with approximately a 3:1 dextro- to levo-amphetamine ratio. Immediate-release tablets and Adderall XR deliver the same mixture at different rates. Controlled trials support ADHD symptom reduction; this is treatment evidence, not proof of general cognitive enhancement.

ASP4345 is an experimental oral drug from Astellas, a positive allosteric modulator of the dopamine D1 receptor: it does not switch the receptor on, but makes it respond to lower concentrations of dopamine. It was developed for the cognitive impairment of schizophrenia. Phase 1 found once-daily pharmacokinetics, entry into the cerebrospinal fluid and, in 48 patients over 14 days, faster reaction times than placebo on two computerized tests. The phase 2 trial then failed: in 233 patients, 50 or 150 mg a day for 12 weeks did no better than placebo on a standard cognitive battery or on a test of everyday functioning, and development was stopped. Those results are posted on the trial registry, which lists no journal publication of them.

BPAP ((−)-1-(benzofuran-2-yl)-2-propylaminopentane) is a research compound made by Joseph Knoll's Budapest group and Fujimoto Pharmaceutical by swapping the phenyl ring of PPAP for a benzofuran, and chosen from 65 analogs as a possible successor to selegiline. In rat tissue it raised the release of dopamine, norepinephrine and serotonin evoked by nerve impulses at femtomolar to picomolar concentrations, without releasing them at rest, and in the shuttle box it was about 130 times as potent as selegiline. It also blocks dopamine and norepinephrine reuptake more potently than cocaine. No human has been studied at any dose, a 2016 longevity benefit in rats was not reproduced in a 2024 study of aged rats, and almost all of the work comes from the inventors and their industrial partner.

Bromantane is a lipophilic adamantane stimulant-anxiolytic developed in the Soviet Union and marketed in Russia as Ladasten for asthenic disorders. A 30-person, single-blind placebo trial reported faster and greater symptom relief, while a 728-patient uncontrolled program reported improvement from day 3; neither result has been independently replicated. Its best-supported mechanism is not direct receptor agonism or dopamine transporter blockade, but altered expression of dopamine-synthesis enzymes in animals.

Concerta is an osmotic extended-release formulation of methylphenidate hydrochloride for ADHD. A controlled pediatric comparison found effects lasting through 12 hours and broadly matching immediate-release methylphenidate given three times daily. It is the same active drug as Ritalin, with a different delivery system.

DL-phenylalanine (DLPA) is a 50:50 mix of the dietary amino acid L-phenylalanine and its mirror image, D-phenylalanine. It is sold for mood and pain on the strength of two 1970s–80s ideas: that L-phenylalanine feeds catecholamine and phenylethylamine synthesis, and that D-phenylalanine slows the breakdown of enkephalins. The human evidence is old and thin. Small German depression studies were positive but had no placebo arm, and the only placebo-controlled chronic-pain trial of D-phenylalanine found no analgesic effect. The strongest modern data concern L-phenylalanine alone: short-term tolerability up to 12 g/day in healthy men and gut-hormone effects at 10 g.

L-THP (levo-tetrahydropalmatine, or rotundine) is a tetrahydroprotoberberine alkaloid used in China as a sedative and analgesic and investigated for substance-use disorders. One 120-person pilot trial reported less heroin craving and more abstinence, but treatment caused markedly more early dropout. A small phase-I study found 30 mg twice daily tolerable for 3.5 days, not proof of long-term efficacy or safety.

L-tyrosine is a dietary amino acid and catecholamine precursor, not a reliably demonstrated everyday nootropic. Small crossover trials suggest that large acute doses can preserve selected attention, working-memory or psychomotor outcomes during sleep loss, cold, noise or demanding multitasking, but reviews judge the evidence heterogeneous and too weak for a firm recommendation. Results in unstressed adults are mixed and baseline-dependent. A meta-analysis found no endurance benefit, although one later 12-person cycling experiment was positive. Four weeks at up to 4 g/day produced no dose-related safety signal in 30 healthy men, but that does not establish long-term or clinical-population safety.

Modafinil is a prescription wakefulness-promoting drug for narcolepsy, obstructive sleep apnea and shift work sleep disorder. It is widely used off-label as a "smart drug". In healthy people who are not sleep-deprived, a meta-analysis found only a small overall cognitive effect, driven mainly by memory updating.

N-acetyl-L-tyrosine (NALT) is a water-soluble acetylated derivative of L-tyrosine. Human evidence is almost entirely intravenous nutrition research, where 35–60% was recovered unchanged in urine and plasma tyrosine often did not rise. There are no cited human oral trials showing that NALT improves cognition, stress performance or energy.

Phenylpiracetam is a Soviet-era piracetam analog with a phenyl ring on the pyrrolidone, developed in 1983 and prescribed in Russia as Phenotropil. Modern work identifies the dopamine transporter as its only significant molecular target, and the two enantiomers do different things. It was the first nootropic banned in sport, in 1998. Its human evidence is substantial but almost entirely Russian and non-randomized: a matched 400-patient stroke-rehabilitation study, a 56-patient comparison against piracetam and a 1170-patient observational program.

PPAP (1-phenyl-2-propylaminopentane) is a research stimulant made in Joseph Knoll's Budapest laboratory as a version of selegiline with the MAO-B inhibition taken out. In rats it improved learning and retention, reversed the learning deficit caused by tetrabenazine and was active in the forced swimming test, without releasing catecholamines the way amphetamine does. No human has been studied at any dose: its inventor wrote in 2001 that, despite his group's efforts, it had never been tested clinically, and almost every experiment comes from the group that invented it.

Ritalin tablets contain immediate-release methylphenidate hydrochloride, a prescription stimulant used for ADHD and narcolepsy. ADHD efficacy is well supported, while its shorter delivery profile means that trial regimens often use multiple daily doses. This page focuses on ordinary tablets, not the separate Ritalin LA formulation.

Sabroxy is a branded bark extract of Oroxylum indicum, the Indian trumpet tree. It is standardized to three flavones: oroxylin A, chrysin and baicalein. One 12-week randomized trial in older adults with memory complaints found better episodic memory than placebo. The same trial found no difference on most individual tests, the MoCA or self-rated cognition. That trial is the only controlled human study of the plant.

Selegiline (L-deprenyl) is an irreversible MAO-B inhibitor created in Joseph Knoll's Budapest laboratory in the 1960s and prescribed for Parkinson's disease and, as a skin patch, for major depression. In early Parkinson's disease 10 mg a day delayed the need for levodopa by about nine months, though whether that was protection or symptom relief was never settled; the patch beat placebo modestly in adult depression and not at all in adolescents. It is broken down to l-methamphetamine and l-amphetamine. Its reputation as an anti-aging drug rests on rat longevity studies that replicated inconsistently, and a Cochrane review found no clinically meaningful benefit in Alzheimer's disease.

Tesofensine is not a GLP-1 anything. It is a triple monoamine reuptake inhibitor - it blocks the transporters for norepinephrine, dopamine and serotonin - originally developed for Parkinson's and Alzheimer's disease, where trials failed but participants lost weight. That observation led to a phase 2 obesity trial in 203 patients: 24 weeks at 0.5 mg gave 9.2% weight loss against 2.0% on placebo, with heart rate up 7.4 beats per minute. It never reached phase 3 for obesity. That trial also carries a Lancet expression of concern, issued in 2013 over under-reporting of adverse effects and never withdrawn. A newer formulation combining tesofensine with metoprolol has been tested in hypothalamic obesity, a condition with almost no other options, giving 6.3% more weight loss than placebo in 21 patients.

Vyvanse is lisdexamfetamine dimesylate, a prodrug converted in blood to dextroamphetamine. It has established ADHD efficacy and a separate US indication for moderate-to-severe binge-eating disorder in adults. Its prodrug design changes delivery but does not remove stimulant adverse effects or misuse potential.