Dopamine

Phenylpiracetam

Phenylpiracetam (phenotropil, carphedon) is a phenylated derivative of piracetam, developed in Russia and used clinically as a nootropic, with reported effects on focus, physical endurance, and tolerance to cold and fatigue. The added phenyl group makes it considerably more potent than the parent racetam and confers a distinct mechanism, selective inhibition of the dopamine transporter, which is thought to underlie its stimulant-like, motivating properties. It was among the first cognitive enhancers prohibited in competitive sport, having been banned by anti-doping authorities in 1998.

DNSP-11

DNSP-11 is a synthetic 11-amino-acid peptide copied from the pro-region of GDNF, a natural protein that helps dopamine-producing brain cells survive. In rats and in a small group of monkeys it raised dopamine activity and protected dopamine neurons against chemical damage, which is why it is discussed as a possible Parkinson's disease treatment. The evidence is entirely animal and cell-culture work, almost all of it from a single laboratory at the University of Kentucky; no person has ever received it in a registered clinical trial, and the receptor it acts on has never been identified. Material sold online under this name is an unapproved research chemical with no human safety data behind it.

L-Tyrosine

L-Tyrosine is an aromatic amino acid used to build proteins and to make several important signaling molecules. Because the body can produce it from the essential amino acid phenylalanine, it is usually classed as non-essential, or conditionally essential when phenylalanine is scarce. It is the raw material for the catecholamine neurotransmitters dopamine, norepinephrine, and epinephrine, as well as for thyroid hormones and the pigment melanin, and it is sold as a supplement studied mainly for mental performance under stress.

Memantine

Memantine (brand names Namenda and Ebixa) is an NMDA receptor antagonist approved for moderate to severe Alzheimer's disease; it calms excess glutamate signaling to protect neurons while leaving the normal signaling needed for memory and learning intact [1][2]. What makes it unusual is its voltage-dependent, fast-off-rate binding; it blocks the constant, low-level 'noise' of glutamate but steps aside when a real learning signal arrives, so it doesn't cloud cognition the way stronger blockers (like ketamine) do. It is also more than a pure NMDA blocker; at or near therapeutic brain concentrations it reaches a spread of remote targets, agonizing the high-affinity state of the dopamine D2 receptor, antagonizing 5-HT3 serotonin receptors and several nicotinic acetylcholine receptors (alpha-7, alpha-4/beta-2, alpha-3/beta-4 and alpha-9/alpha-10), and weakly engaging sigma-1 receptors; see the affinity table below for the full fingerprint. Beyond Alzheimer's it is being investigated for a range of conditions; it shows the most promise for the negative symptoms of schizophrenia (social withdrawal, apathy, blunted motivation) and as a mood stabilizer in bipolar disorder, with earlier signals in ADHD (often as an adjunct to a stimulant), anxiety and OCD, and autism.

Paraxanthine

Paraxanthine is what caffeine mostly becomes. Around 70 to 80 percent of a caffeine dose is converted by the liver enzyme CYP1A2 into paraxanthine, so for most of the time a coffee is working, the compound doing the work is this one [14]. Selling it directly is an attempt to skip a step that varies enormously between people: CYP1A2 activity differs several-fold across individuals, which is a large part of why the same espresso is pleasant for one person and unpleasant for another. Human trials are small but real, and they point at improved cognition at modest doses with less of the sleep disruption caffeine causes [4][6]. It is the most credible caffeine alternative on this site, and the evidence base behind it is still thin and largely tied to the company selling it.

Phenylalanine

Phenylalanine is an essential amino acid and the first step in making dopamine and noradrenaline: the body converts it to tyrosine, tyrosine to L-DOPA, and L-DOPA to dopamine. That chain is the entire basis for taking it, and it is also the reason to be measured about it, because supplying more of the first ingredient does not reliably speed up a pathway that is regulated further downstream. The best-supported use is not mood at all; L-phenylalanine combined with light therapy has a real if modest evidence base in vitiligo [9][10]. The critical safety fact is short and absolute: anyone with phenylketonuria must not take it [7].

Pregnenolone

Pregnenolone (3β-hydroxypregn-5-en-20-one) is an endogenous neurosteroid and the first steroid synthesized from cholesterol, making it the obligatory precursor of every other steroid hormone, including progesterone, dehydroepiandrosterone (DHEA), cortisol, the sex steroids, and the neuroactive metabolites allopregnanolone and pregnenolone sulfate. Once regarded as a metabolically inert intermediate, it is now recognized as a signaling molecule in its own right, most notably as an endogenous negative allosteric modulator of the type-1 cannabinoid receptor (CB1, the principal brain receptor for THC) and as a ligand for microtubule-associated protein 2 (MAP2, a neuronal cytoskeletal scaffolding protein), through which it promotes microtubule assembly and neurite outgrowth. Synthesized de novo in the brain by neurons and glia, it is investigated as an adjunctive treatment for schizophrenia, mood disorders, and cannabis-related conditions, and is sold over the counter as a nootropic and hormonal supplement.

Sabroxy

Oroxylin A is a plant flavonoid from the bark of the Indian trumpet tree (Oroxylum indicum) and from Chinese skullcap; consumers almost never buy the pure compound, they buy Sabroxy, a standardised bark extract in which oroxylin A is one of three flavonoids. It is marketed for memory and focus, and the animal work points to two mechanisms: it blocks the benzodiazepine site on the GABA-A receptor, releasing the brain's main braking signal, and it slows dopamine reuptake in roughly the way ADHD stimulants do. Human evidence is thin and rests on a single 12-week trial in 82 older adults with memory complaints; that trial was paid for by the ingredient's manufacturer, had a company founder as a co-author, found gains on some memory tasks but not most other measures, and applied no statistical correction for testing many outcomes at once. A separate Phase I study showed pure oroxylin A is tolerated up to 2400 mg in healthy volunteers, but no trial has ever shown the pure compound improves cognition in people.

Sulbutiamine

Sulbutiamine is a synthetic derivative of thiamine, or vitamin B1, formed by joining two modified thiamine molecules into a fat-soluble disulfide. This lipophilic structure lets it cross the blood-brain barrier and raise thiamine levels in the brain more readily than thiamine itself, which distinguishes it from benfotiamine, a related derivative that raises thiamine chiefly in peripheral tissues. Developed in Japan and marketed under names such as Arcalion, it is used to treat asthenia, a state of persistent weakness and fatigue, and is also taken off-label as a nootropic; more recent work implicates its disulfide group in cellular thiol-redox regulation.

Modafinil

Modafinil is a prescription wakefulness-promoting drug, approved in the United States in 1998 for excessive sleepiness caused by narcolepsy, obstructive sleep apnea, and shift work disorder. It works mainly by blocking the dopamine transporter, the protein that clears dopamine out of the synapse; human brain imaging confirms it occupies roughly half of those transporters at ordinary doses, although it binds them far more weakly than classic stimulants do. The evidence that it reduces sleepiness in the three approved sleep disorders is strong and rests on large placebo-controlled trials, but the evidence that it improves thinking in healthy, well-rested people is much weaker; the best meta-analysis found only a small overall effect confined to one narrow memory task. It is a Schedule IV controlled substance in the United States, banned in competition by WADA, and carries warnings for rare but serious skin reactions and for making hormonal birth control less reliable.

Armodafinil

Armodafinil is the prescription wakefulness drug sold as Nuvigil; it is one of the two mirror-image halves of modafinil, the longer-lasting half, so it does much the same job at a somewhat lower dose. In the United States it is approved only to reduce excessive sleepiness in adults with narcolepsy, obstructive sleep apnea, or shift work disorder, and the evidence for those three uses is genuinely solid; several 12-week placebo-controlled trials show people stay awake longer, though the benefit is measured in a few extra minutes of resisting sleep rather than a cure. Its one well-supported molecular action is weak blockade of the dopamine transporter, which brain scans confirm happens at ordinary doses; the histamine and orexin explanations that circulate online come from studies of modafinil, not of armodafinil itself. Outside the sleep indications the record thins out fast and is often negative, including a clean phase 3 failure for cancer-related fatigue, and this is a Schedule IV controlled drug carrying a pregnancy registry signal for birth defects.

CE-123

CE-123 is a next-generation, thiazole-based modafinil analogue engineered for selective dopamine transporter inhibition and cognitive enhancement. In preclinical studies it sharpens memory and cognitive flexibility while crossing into the brain far more effectively than modafinil, and with less impulsivity. For research focused on motivation, focus, and cognition, CE-123 is a standout modern nootropic candidate.

Bromantane

Bromantane is an adamantane-derived actoprotector that delivers clean, non-jittery energy by increasing the body's own dopamine synthesis rather than forcing a release. Prized for boosting physical and mental stamina while carrying a genuine anti-anxiety quality, it stands out as a rare stimulant that builds resilience without a crash or dependence. For those seeking durable drive and stress resistance, bromantane is a uniquely compelling choice.

9-Me-BC

9-Me-BC is a small synthetic molecule from the beta-carboline family, chemically close to compounds that occur naturally in coffee, cooked meat and tobacco smoke; it is sold online as a nootropic and has never been approved as a medicine anywhere. In cell cultures and in rodents it raises dopamine levels, protects and partly regrows dopamine-producing neurons, and improved maze learning in rats, which is why it was proposed as a possible Parkinson's disease drug. The evidence is entirely preclinical; there is no human trial, no human dosing study and no human safety data at all, and almost every positive finding comes from a single research group in Germany. Two specific concerns remain unresolved: it inhibits the enzyme MAO-A at low concentrations, the same mechanism that makes prescription MAOI antidepressants risky with certain foods and drugs, and enzymes in the brain can convert it into a closely related molecule that is itself an established nerve toxin.

4 outlets

PPAP

PPAP is a laboratory compound derived from selegiline that was designed to stimulate the brain without the uncontrolled neurotransmitter dumping that amphetamines cause. In rats it increases the dopamine and noradrenaline released when a nerve cell actually fires, an effect its developers named a catecholaminergic activity enhancer effect; unlike selegiline it does not block the enzyme MAO-B. A 2026 screening study also found it blocks dopamine reuptake, slightly more strongly than amphetamine did in the same assay. Almost the entire evidence base is rat and cell work from one Hungarian laboratory; PPAP has never been given to a human in any published study, so no human dose or safety information exists, and it has since appeared as an unregulated substance on the European drug market.

BPAP

BPAP is an experimental laboratory compound created in the late 1990s by the Hungarian and Japanese team behind selegiline; it has never been approved as a medicine in any country. It is described as a "monoaminergic activity enhancer", meaning that in animal tissue it makes dopamine, noradrenaline and serotonin neurons release more transmitter when they fire, rather than forcing transmitter out the way amphetamine does; at higher concentrations it also blocks dopamine and noradrenaline reuptake. Essentially all the evidence comes from rats, mice and cell cultures, and almost all of it was produced by the two groups with a stake in the compound, namely Knoll's Semmelweis University laboratory and Fujimoto Pharmaceutical Corporation. No clinical trial in humans has ever been run or even registered, so claims about memory, mood, longevity or anti-aging benefit in people rest on no human evidence at all.

CDP-Choline

CDP-choline (citicoline, cytidine diphosphate-choline) is a naturally occurring compound that the body uses as an intermediate in making phosphatidylcholine, a major building block of cell membranes. Taken as a drug or dietary supplement, it supplies choline and cytidine to the brain and is studied for cognition, stroke recovery, and certain eye conditions. It is sold as a prescription medicine in some countries and as an over-the-counter supplement in others.

5 outlets

PRL-8-53

PRL-8-53 is a classic research nootropic famous for a single striking human study in which low oral doses significantly improved the retention of newly learned verbal information [1]. Chemically a methyl benzoate compound developed in the 1970s, it was reported to sharpen memory while potentiating the brain's dopaminergic and stimulant signaling [1][2]. Its reputation rests almost entirely on that early double-blind trial, as PRL-8-53 has never been independently replicated or brought to market, and it remains an obscure but intriguing research chemical [1][2].

Tropisetron

Tropisetron is a prescription anti-nausea drug that blocks the serotonin 5-HT3 receptor, and it is used to stop the vomiting caused by chemotherapy or by surgery; it has been sold for that purpose since 1992 in Europe, Japan, Australia and much of Asia, but it was never approved in the United States. What sets it apart from the other drugs in its class is that it also binds tightly to a brain receptor called the alpha-7 nicotinic acetylcholine receptor, which is why researchers have tested it for fibromyalgia pain, for thinking problems in schizophrenia, and in animal models of Alzheimer's and Huntington's disease. The anti-nausea use is solidly established; every other use rests on small short trials, mostly fewer than 45 people and under two weeks long, or on animal work, and no regulator anywhere has approved it for any of them. Anyone reading the older literature should also know that a large slice of the post-surgical anti-nausea evidence base was fabricated and later retracted, so individual old trials in that area carry very little weight on their own.

Selegiline

Selegiline, also known as L-deprenyl, is a selective and irreversible inhibitor of monoamine oxidase B (MAO-B), used in the treatment of Parkinson's disease and, in a transdermal patch form, of major depressive disorder. At low doses it selectively spares MAO-A, which avoids the dietary tyramine restrictions required by older monoamine oxidase inhibitors, though this selectivity is lost at higher doses. It is marketed under names including Eldepryl, Zelapar, and, as a skin patch, Emsam.

Tesofensine

Tesofensine is a triple monoamine reuptake inhibitor, originally investigated for Parkinson's and Alzheimer's disease, that produced some of the largest weight losses reported for an appetite-suppressing drug. By simultaneously blocking the reuptake of dopamine, noradrenaline, and serotonin it curbs hunger and increases satiety, and it additionally silences appetite-driving GABAergic neurons in the hypothalamus. In a phase 2 obesity trial it produced weight loss roughly twice that of the obesity medications approved at the time, though that trial has carried an expression of concern over its adverse-effect reporting since 2013; it remains investigational, with cardiovascular effects among the safety considerations.

RGPU-95

RGPU-95 is an experimental compound studied in Russian pharmacological research as a structural analog of fenotropil, better known as phenylpiracetam, a nootropic of the racetam family. In animal experiments it has shown anxiety-reducing and antidepressant-like effects, in some measures exceeding those of its parent compound. It is an obscure investigational substance with essentially no human data, and it is not an approved medicine or recognized supplement ingredient anywhere.

Stimulant

1,3-DMAA

1,3-DMAA (1,3-dimethylamylamine, methylhexanamine) is a potent aliphatic amine stimulant that defined the golden era of hardcore pre-workouts, prized for driving energy, appetite suppression, and razor focus. Originally patented in the 1940s as a nasal decongestant, it delivers an amphetamine-adjacent lift through indirect adrenergic stimulation and a distinctive vasoconstrictive edge. Its reputation as one of the most intense stimulants ever sold in sports nutrition kept demand high even as regulators moved to restrict it.

Stimulant

1,4-DMAA

1,4-DMAA (1,4-dimethylamylamine) is an experimental aliphatic amine stimulant that emerged as a next-generation successor to the banned 1,3-DMAA, marketed for the same hard-hitting pre-workout energy and focus. As a positional isomer of the classic DMAA molecule, it gives formulators a structurally distinct route to intense adrenergic stimulation. It remains a rare, sought-after ingredient in a handful of underground sports and weight-loss products, appealing to enthusiasts chasing the original DMAA experience.

Antidepressant

Amisulpride

Amisulpride is a second-generation (atypical) antipsychotic of the benzamide class, used chiefly to treat schizophrenia and, at low doses in some countries, depressive conditions such as dysthymia. A low-dose intravenous form is also used to prevent and treat postoperative nausea and vomiting. It works as a selective blocker of dopamine D2 and D3 receptors, with additional antagonism of the serotonin 5-HT7 receptor that is thought to contribute to its mood effects [1][3].

Bupropion

Bupropion is an atypical antidepressant of the aminoketone class that works mainly as a norepinephrine-dopamine reuptake inhibitor. It is used to treat major depressive disorder and seasonal affective disorder and, under a separate brand, as an aid to quitting smoking; it is also part of a combination weight-loss product. Unlike many antidepressants it has little direct effect on serotonin and rarely causes sexual dysfunction or weight gain.

Antipsychotic

Cariprazine

Cariprazine, sold as Vraylar (and Reagila in Europe), is a third-generation antipsychotic. Rather than simply blocking dopamine, it is a dopamine D3-preferring D2/D3 receptor partial agonist, meaning it partly activates those receptors and buffers dopamine signaling up or down toward a middle setpoint; it is also a 5-HT1A partial agonist and a 5-HT2B antagonist. It is used for schizophrenia and for bipolar disorder, including bipolar depression, and its standout feature is an unusually high affinity for the D3 receptor that is thought to help the negative and cognitive symptoms ordinary antipsychotics tend to leave untouched.

Chlodantane

Chlodantane is an adamantane-derived adaptogen developed in Russian pharmacology to rapidly boost the body's resistance to physical, chemical, and thermal stress. A close relative of bromantane, it pairs fast-acting adaptogenic effects with immune-stimulating, membrane-protective activity. For those interested in stress resistance and resilience compounds, chlodantane is an intriguing member of the adamantane family.

Cholinergic

Cytisine

cytisine (tabex, cytisinicline) is a natural plant-alkaloid nicotinic partial agonist and the structural parent of varenicline; a high-affinity alpha4beta2 partial agonist, high-efficacy alpha3beta4 agonist, and only a weak partial agonist at the alpha6beta2* dopamine-terminal receptors that gate nicotine reward; a cheap, trial-validated smoking-cessation drug rather than a nootropic.

DHEA

Dehydroepiandrosterone (DHEA) is an endogenous androstane neurosteroid and the most abundant circulating steroid hormone in humans, secreted chiefly by the adrenal cortex and also synthesized de novo within the central nervous system. It functions primarily as a precursor to androgens and estrogens, yet exerts direct actions on the brain by acting as an agonist at the sigma-1 receptor (an endoplasmic reticulum chaperone protein that shapes calcium and neurotrophic signaling), as a positive modulator of NMDA receptor (the principal excitatory glutamate ion channel involved in learning) signaling, and, chiefly as its sulfate ester DHEAS, as a negative allosteric modulator of the GABA-A receptor (the brain's main inhibitory ion channel). DHEA additionally behaves as a functional anti-glucocorticoid, buffering the neurotoxic effects of cortisol, and shows neuroprotective and mood-related activity in preclinical and clinical studies. Circulating concentrations peak in early adulthood and decline markedly with age, a phenomenon termed adrenopause that has driven its widespread use as an over-the-counter supplement.

Guarana

Guarana is a climbing plant native to the Amazon basin, classified as Paullinia cupana in the soapberry family Sapindaceae, whose seeds are prized for an unusually high caffeine content. Indigenous peoples of the region, including the Sateré-Mawé, have long processed the seeds into a dried paste used to brew a stimulating beverage. Today the seed powder and its extracts are used chiefly as a caffeine source in soft drinks, energy drinks, and dietary supplements.

Hydrafinil

Hydrafinil, also called 9-fluorenol or 9-hydroxyfluorene, is a simple laboratory chemical that Cephalon tested around 2012 while looking for a successor to the wakefulness drug modafinil; despite the similar sounding name it is not chemically related to modafinil and belongs to a different chemical family. In the single rat experiment that exists it kept animals awake longer than modafinil did at the same injected dose, after which the programme was dropped with no published reason and never reached a human trial. The entire human record is one anti-doping study in which three healthy men each swallowed a single 50 mg dose so that laboratories could learn to detect it in urine; nothing at all has been published on whether it improves alertness, attention or fatigue in people, and nothing has been published on its safety. It is banned in competition by the World Anti-Doping Agency and is not an approved medicine in any country.

Neuroprotection

Lithium

Lithium is the lightest metal, taken not as the pure metal but as a salt such as lithium carbonate, citrate, or orotate. It is the long-standing gold-standard mood stabilizer for bipolar disorder, with unusually strong anti-suicidal and neuroprotective properties that other mood drugs do not match. It works largely by damping down two intracellular enzymes, GSK-3 and inositol monophosphatase, which nudges the brain toward neuroprotective, growth-promoting signaling.

Dopaminergic

Mucuna Pruriens

Mucuna pruriens, commonly called velvet bean or cowhage, is a tropical climbing legume of the family Fabaceae whose seeds are a rich natural source of levodopa (L-DOPA), the precursor of the neurotransmitter dopamine. Long used in Ayurvedic medicine, its seed extracts are marketed as dietary supplements and have been studied as a plant-based option in Parkinson disease. The plant is also notorious for the fine hairs on its pods, which cause intense itching on contact with skin.

N-Acetyl L-Tyrosine (NALT)

N-Acetyl L-Tyrosine (NALT) is an acetylated, more water-soluble form of the amino acid L-tyrosine, originally introduced as a tyrosine source for intravenous nutrition. It is widely marketed as a nootropic on the premise that tyrosine is the precursor of the catecholamine neurotransmitters dopamine and norepinephrine. However, human and animal studies indicate that N-Acetyl L-Tyrosine is converted to free tyrosine inefficiently, with much of an infused dose excreted unchanged in the urine.

Nicergoline

nicergoline (sermion) is a semisynthetic ergoline nootropic-vasodilator; a potent alpha-1 blocker that also boosts cholinergic/neurotrophic tone, with modest but real cochrane-backed benefit in age-related and vascular cognitive decline, tempered by ergot-class fibrosis risk on long timelines.

Supplement

Pyridoxal-5-Phosphate

Pyridoxal-5-phosphate, often abbreviated PLP or P5P, is the biologically active coenzyme form of vitamin B6. It serves as an essential helper molecule for well over a hundred different enzymes, most of them involved in the metabolism of amino acids and the manufacture of neurotransmitters. The body makes PLP from the various dietary forms of vitamin B6, and it is also sold directly as a supplement marketed as a ready-to-use form of the vitamin.

Rasagiline

Rasagiline is a prescription tablet for Parkinson's disease that permanently switches off monoamine oxidase B, the enzyme that breaks down dopamine in the brain; the effect is to make what dopamine remains last longer. Four large placebo-controlled trials show a real but modest symptom benefit, whether taken alone in early disease or added to levodopa later, where it removes roughly one hour per day of the time when levodopa is not working. Whether it actually slows the disease itself is unsettled; in the ADAGIO trial the 1 mg dose met all three of its targets while the 2 mg dose failed them, and that contradiction was never resolved. Trials in multiple system atrophy and in ALS were negative, and no evidence supports rasagiline as a cognitive enhancer in healthy people.

Antipsychotic

Risperidone

Risperidone is a second-generation (atypical) antipsychotic used for schizophrenia, bipolar mania and irritability in some conditions. Like other atypicals it blocks both dopamine D2 and serotonin 5-HT2A receptors, which broadens its effect and, at moderate doses, softens the movement side effects seen with older drugs. It is not recreational; it tends to feel sedating and flattening rather than pleasant.

Adaptogen

Saffron

Saffron is a spice obtained from the dried red stigmas of the flower Crocus sativus, and it is among the most expensive spices in the world by weight. Beyond its long use in cooking as a coloring and flavoring, it has been investigated as a herbal remedy, most notably for depression and low mood. Its characteristic color, taste, and aroma come from the compounds crocin, picrocrocin, and safranal.

Salicin

Salicin is an alcoholic beta-glucoside and a principal salicylate of willow (Salix) and poplar bark and meadowsweet, historically valued as a botanical analgesic and the conceptual forerunner of aspirin. Following ingestion it is hydrolyzed and oxidized to salicylic acid, the same active metabolite that mediates aspirin's effects, though at doses that spare much of the gastric irritation associated with acetylsalicylic acid. Mechanistic studies attribute its anti-inflammatory and antioxidant actions to suppression of the NF-kappaB and MAPK signaling pathways and activation of the Nrf2-heme oxygenase-1 axis, with additional contributions from co-occurring polyphenols and downstream catechol metabolites; salicin has also been identified as an agonist of the bitter taste receptor TAS2R16, a receptor-mediated route to resolving inflammation. Standardized willow bark preparations are used mainly for musculoskeletal and inflammatory pain, and their clinical activity is not fully accounted for by salicin content alone.

SSRI

Sertraline

Sertraline is a selective serotonin reuptake inhibitor (SSRI) prescribed mainly as an antidepressant. It is approved for major depressive disorder together with several anxiety-spectrum conditions, including obsessive-compulsive disorder, panic disorder, social anxiety disorder, post-traumatic stress disorder, and premenstrual dysphoric disorder. Introduced by Pfizer in the early 1990s and sold most widely under the brand name Zoloft, it is among the most frequently prescribed medicines of its class.

Sipagladenant

Sipagladenant (development code KW-6356; CAS 858979-50-7) is an investigational, orally active, highly selective antagonist and inverse agonist of the adenosine A2A receptor developed by Kyowa Kirin for Parkinson's disease. It belongs to the non-dopaminergic class of antiparkinsonian agents typified by istradefylline, but in vitro studies distinguish it by insurmountable antagonism, very slow receptor dissociation, and inverse-agonist activity that suppresses the constitutive signaling of the A2A receptor. Because A2A receptors are densely co-expressed with dopamine D2 receptors as A2A-D2 heteromers on striatopallidal neurons of the indirect motor pathway, blockade of A2A relieves the adenosine-mediated brake on D2 signaling and improves motor output without directly stimulating dopamine receptors. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) treated marmosets it reversed motor disability as monotherapy, produced greater anti-parkinsonian activity than istradefylline, and potentiated levodopa with a low propensity to induce dyskinesia; a placebo-controlled trial in early, untreated Parkinson's disease reported improvement in MDS-UPDRS Part III scores. Sipagladenant remains a clinical-stage compound; it is not approved for any indication, and much of its long-term efficacy and safety profile is still being characterized.

Analgesic

Tetrahydropalmatine

L-THP (levo-tetrahydropalmatine) is a plant alkaloid from Corydalis and related herbs with a long history in traditional Chinese medicine for its calming, sedative, and pain-relieving properties. Modern research has clarified its mechanism as a dopamine receptor modulator, and it has been carried all the way into a human clinical study for cocaine use disorder, an unusually strong evidence base for a botanical compound. For those exploring natural approaches to relaxation, sleep, and discomfort, L-THP is a genuinely well-studied and intriguing choice.

Theacrine

Theacrine is a naturally occurring purine alkaloid, chemically 1,3,7,9-tetramethyluric acid, that is closely related to caffeine and found in the leaves of kucha tea (Camellia assamica var. kucha) and in the cupuacu fruit. It has stimulant-like properties and, like caffeine, acts on adenosine and dopamine signaling to influence energy, alertness, and locomotor activity [1]. Sold as a dietary supplement, often under the trade name TeaCrine, it has drawn attention as a longer-acting alternative to caffeine that appears less prone to tolerance with repeated use [2].

Stimulant

Theobromine

Theobromine is a bitter methylxanthine alkaloid and the principal stimulant compound of the cacao plant (Theobroma cacao), giving chocolate and cocoa much of their mild pharmacological activity. Chemically it is 3,7-dimethylxanthine, an isomer of theophylline and a close relative of caffeine, and it also forms in the human body as a major breakdown product of caffeine [1][3]. It has gentle effects on the heart, blood vessels, airways, and kidneys, and unlike caffeine produces little central-nervous-system stimulation; it is well tolerated in people but is toxic to dogs and some other animals [1].

Antidepressant

Tranylcypromine

Tranylcypromine is an antidepressant of the monoamine oxidase inhibitor (MAOI) class, used mainly for major depression that has not responded to other treatments [1][2]. It works by irreversibly blocking monoamine oxidase, the enzyme that breaks down mood-related neurotransmitters, and it is chemically related to amphetamine [1]. Introduced around 1960 and sold under the brand name Parnate, it requires a tyramine-restricted diet because of the risk of dangerous blood pressure spikes.

Uridine

Uridine is a nucleoside, one of the building blocks of ribonucleic acid (RNA), formed from the base uracil joined to the sugar ribose. It occurs naturally in the body, where it can be made from scratch, and in foods, and it takes part in RNA synthesis, sugar metabolism and the production of cell-membrane phospholipids. As a supplement, usually in the form of uridine monophosphate, it has been studied for effects on brain phospholipids, memory and mood [1][3].

Uridine Monophosphate

Uridine monophosphate (UMP) is the nucleotide form of uridine and the most common way uridine is sold as a nootropic. It feeds the pathway that builds neuronal membranes and supports acetylcholine and dopamine signaling; it is the uridine in the popular Mr Happy stack alongside omega-3s and a choline source.

Uridine Triacetate

Uridine triacetate is a prodrug of uridine; three acetate groups make it far more orally bioavailable than plain uridine, so it delivers much more uridine to the body and brain. It is used both clinically (as Vistogard/Xuriden) and popularly in nootropic uridine stacks for memory and mood.

Supplement

Vitamin B6 (Pyridoxine)

Vitamin B6 is a water-soluble essential nutrient that exists as several interconvertible forms; pyridoxine is the stable form used in most supplements and food fortification. In the body it is converted to pyridoxal-5-phosphate (PLP), the active coenzyme that drives well over a hundred distinct enzyme reactions, most of them in amino acid metabolism and in the synthesis of neurotransmitters such as serotonin, dopamine, and GABA. Because of that reach it is tied to mood, energy metabolism, and the clearing of homocysteine, and it is a first-line remedy for the nausea of early pregnancy and a popular one for premenstrual symptoms. It is cheap and generally safe, but chronic high doses are the one real catch, since they can cause a slowly reversible sensory nerve injury.

Thozalinone

Thozalinone is a classic oxazolinone psychostimulant from the same chemical family as pemoline, originally developed in the 1960s as a mood-lifting antidepressant and appetite suppressant. It delivers amphetamine-like central stimulation and energizing, drive-boosting effects through dopaminergic pathways. A largely forgotten agent of the early psychopharmacology era, it has drawn renewed curiosity as a stimulant research chemical.

MPAP

MPAP is an experimental laboratory chemical from the Hungarian "enhancer" series that also produced PPAP and BPAP; it is a chemical relative of the amphetamines but it does not work like one, since it does not force neurotransmitter out of nerve cells. In rats it appears to make catecholamine and serotonin neurons release a little more transmitter when those neurons are already firing, and it did so at about one fifth of the dose PPAP required; that single set of animal experiments is essentially the entire evidence base. There are no human studies, no established dose, no safety or toxicology data, and no measured binding constants for MPAP, and the popular explanation of how it works (TAAR1 activation) comes from experiments on its cousin BPAP rather than on MPAP. It is best read as a compound whose profile is inferred by analogy; the confident descriptions of it circulating online outrun the actual data by a wide margin.

Anxiolytic

Flibanserin

Flibanserin is a serotonergic medication approved to treat hypoactive sexual desire disorder (HSDD) in premenopausal women, sold under the brand name Addyi. It was first developed as an antidepressant but was repurposed after it appeared to influence sexual desire. Unlike drugs for erectile dysfunction, it is taken daily and acts on the brain rather than on blood flow. Its 2015 approval by the United States Food and Drug Administration was controversial, following two earlier rejections and a debate over whether its modest benefits justified its risks.

Blend

Levodopa + Carbidopa

Levodopa + carbidopa is a fixed-dose combination medication used chiefly to treat Parkinson's disease. Levodopa is a precursor that the brain converts into dopamine, the neurotransmitter that is depleted in the disease, while carbidopa prevents levodopa from being broken down before it reaches the brain. Sold under brand names such as Sinemet, the pairing remains the most effective symptomatic treatment for Parkinson's disease.