concepts

the ideas that come up again and again across the compound entries, explained like a normal person would. each one's got the plain-english version up top, then a deeper dive underneath, all cited and linked back into the wiki. new concepts get added as the catalogue grows.

browse collections browse by effect full index

43 concepts · plain-english & cited

Adaptogens & the stress responseWhere the word came from, why the definition resists testing, what the modern randomised trials actually found.
Ampakines & AMPA receptorsThe AMPA receptor is glutamate's fast workhorse and ampakines turn it up. The mechanism is one of the best characterised in this field; the clinical record is one of the worst.
Anabolic-androgenic steroidsWhat AAS are and how they build muscle through one receptor, why the anabolic and androgenic effects cannot be fully separated, and what the evidence says about the costs.
Antioxidants & oxidative stressThe free-radical story told straight: what oxidative stress is, why the body needs some of it, and why the large antioxidant supplementation trials came back negative or worse.
Anxiolytics & GABAHow calming compounds work: GABA is made from glutamate, released by local interneurons rather than a projection system.
BDNF & neuroplasticityWhat BDNF is, why it is tied to learning and mood, what genuinely raises it, why serum measurements are shaky, and why the small-molecule TrkB agonist story has not replicated.
Choline sources comparedCholine bitartrate, Alpha-GPC, CDP-choline and the rest: what each one actually delivers, what the barrier transporter allows through, and which claims have a trial behind them.
The cholinergic systemAcetylcholine, the brain's attention and memory transmitter: where its neurons live, how it is built and destroyed in milliseconds, what fails in Alzheimer's disease.
DissociativesThe drugs that detach mind from body by blocking the NMDA channel: how the block works, why the label predicts less than it seems to, and the specific harms.
The dopaminergic systemDopamine is not the pleasure molecule. A tour of the nine cell groups, the four pathways they form, what the signal actually encodes.
The endocannabinoid systemThe body's own cannabis-like signalling network: how retrograde messengers made on demand work, the enzymes that build and destroy them, and what drugs aimed at the system have actually achieved.
EntactogensThe MDMA class: why it is a category of its own, how transporter reversal produces it, what the neurotoxicity evidence really shows, and where the clinical work stands.
EugeroicsWakefulness-promoting agents like modafinil: what the class name claims, what the imaging data actually showed, and how the family compares once you look at the trials.
GLP-1 & metabolic peptidesThe gut-hormone drugs that reshaped obesity medicine: what GLP-1 does, the chemistry that made a two-minute hormone last a week, what the outcome trials showed, and the real costs.
Growth hormone & secretagoguesHow the growth-hormone peptides work: the pulse the pituitary already runs, the two receptors that drive it, why the pairs are combined, and what the controlled trials actually found.
The HPA axis & cortisolThe body's stress command chain and its hormone: how the relay fires, why it pulses rather than pours, what chronic elevation costs, and which compounds have real trial data against it.
Mitochondria & cellular energyThe cell's power plants and the ATP they make: how the electron transport chain works, why function falls with age, what the mutator mouse did and did not prove, and what the human trials found.
Neurotransmitters 101A map of the brain's chemical messengers; the accelerator and the brake, the six modulators that set tone, the life cycle every drug interrupts somewhere, and what the field still does not know.
NMDA, glutamate & memoryGlutamate is the brain's main go signal and has no off switch except transporters. The NMDA receptor is the coincidence detector that turns experience into memory.
Nootropic stackingHow to think about combining compounds: what synergy actually means, which classic pairings have trial data, how to test a stack on yourself without fooling yourself.
What is a nootropic?Where the word came from, the five criteria almost nothing meets, the families it now covers, and how far the human evidence actually goes.
Peptides & bioregulatorsWhat a peptide actually is, why almost all of them are injected, how the good ones are engineered to survive, and what the "bioregulator" idea does and does not have behind it.
Half-life & bioavailabilityWhat half-life and bioavailability actually mean, why route decides the dose, how liver enzymes and transporters drive interactions.
Psychedelics & 5-HT2AOne receptor ties LSD, psilocybin, mescaline and the 2C-x together; what the evidence for that actually is, where it stops explaining things, and what the clinical record shows.
RacetamsThe practical rundown of the family: what each member changes, how far the human evidence goes, why doses run from tens of milligrams to grams, and what the suffix does not tell you.
Research chemicals & harm reductionWhat "for research use only" really means, why these compounds keep appearing, the specific ways they go wrong, and which harm-reduction measures have evidence behind them.
SARMs explainedSelective androgen receptor modulators: where the selectivity idea comes from, what the clinical trials actually measured, why none is approved, and what analysis says is really in the bottle.
The serotonergic systemSerotonin is not the happiness chemical. Where the raphe neurons project, why gut serotonin and brain serotonin are separate pools, what the depletion studies really showed.
Sleep, melatonin & circadian rhythmWhy sleep is the brain's maintenance window, how the 24 hour clock is set, why melatonin is a timing signal rather than a sedative, and what the trials on the common sleep aids actually show.
Tolerance, dependence & down-regulationWhy the same dose stops working, why stopping feels worse than baseline, the four levels the adaptation happens at, which classes are genuinely dangerous to stop.
Acetylcholine receptors (nicotinic & muscarinic)A plain-language tour of acetylcholine's two receptor families; fast nicotinic ion channels and slower muscarinic GPCRs, and why both matter for memory.
Adenosine receptors (A1, A2A, A2B, A3)How four receptors for one energy-metabolism byproduct build sleep pressure, set alertness and guard stressed tissue, and why blocking two is caffeine.
Adrenergic receptors (alpha & beta)Two transmitters, nine receptors and three G proteins; that arithmetic is why one squirt of noradrenaline tightens a blood vessel, opens an airway and mobilises fat at the same moment.
Cannabinoid receptors (CB1 & CB2)How CB1 and CB2 differ in location, signalling and role, why efficacy separates THC from the synthetics that hurt people, and what tolerance looks like.
Dopamine receptors (D1-D5)The five dopamine receptors, split into D1-like (Gs) and D2-like (Gi/o); how that one coupling difference shapes stimulants, antipsychotics and tolerance.
GABA receptors (GABA-A & GABA-B)GABA is the brain's main brake; GABA-A is a fast chloride channel, GABA-B a slow G-protein switch, and between them they carry almost every sedative in use.
Glutamate receptors (NMDA, AMPA, kainate, mGluR)Glutamate is the brain's main excitatory transmitter; its receptors split into fast ion channels (NMDA, AMPA, kainate) and slower metabotropic mGluRs.
Opioid receptors (mu, delta, kappa, NOP)How mu, delta, kappa and NOP split analgesia from euphoria, dysphoria and dependence, and why tolerance to different effects runs on different clocks.
Serotonin (5-HT) receptorsA plain-language tour of the serotonin receptor families, 5-HT1 through 5-HT7, what each one couples to, which drugs hit them, and where the subtype you did not intend to touch causes the harm.
Sigma receptors (sigma-1 & sigma-2)Sigma is the odd one out: not a neurotransmitter family, not a GPCR, not an ion channel, with no agreed natural ligand, and a sigma-2 that was not even identified as a protein until 2017.
PPAP, BPAP and the activity enhancersA small family of amphetamine-derived research compounds that, in rat experiments, make neurons release more transmitter per nerve impulse rather than forcing it out the way a stimulant does.
Pyrrolidones and the racetam familyEvery racetam is built on 2-pyrrolidinone, the small ring you get by folding GABA shut, and that shared skeleton is the only thing they reliably share.
How to read a chemical classSome class names describe what a molecule looks like and some describe what it is supposed to do; telling the two apart is most of the skill.