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Psychedelic and Psychopharmacology Glossary

The Psychedelic and Psychopharmacology Glossary defines the terms used across the Library's plant-medicine and harm-reduction material and in works like PIHKAL and TIHKAL. Definitions are written in the Library's own words for reference and education; for the full compound entries the Library links out to Erowid (see PIHKAL and TIHKAL). It is part of the Glossaries section.

This is reference, not advice or encouragement. Where a term touches safety, the safer-practice meaning is given.

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25I-NBOMe — a potent synthetic phenethylamine full agonist at 5-HT2A active at microgram doses ($250\text{–}800\,\mu\text{g}$), dangerously mis-sold on blotter paper as counterfeit LSD; lacks an indole ring (no Ehrlich reaction) and exhibits a bitter, tongue-numbing metallic taste; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.
2C-T Series — Alexander Shulgin's 4-alkylthio-substituted phenethylamines (2C-T-2, 2C-T-7, 2C-T-21) where sulfur replaces oxygen, increasing lipophilicity and 5-HT2A binding depth, metabolized by FMOs; see Thiols and Oxygen Congeners in Medicinal Chemistry.
32B1T (3-methyl-2-butene-1-thiol) — a prenylated volatile sulfur compound (VSC) responsible for the pungent, skunky stench of cured cannabis flower, detectable by human olfactory receptors at parts-per-trillion levels; see Thiols and Oxygen Congeners in Medicinal Chemistry.
5-HT2B Valvular Heart Disease (VHD) — mitogenic proliferation and fibrotic thickening of heart valve leaflets induced by potent full agonists (norfenfluramine, 6-APB, MDA), leading to valvular regurgitation and heart failure; see David E Nichols, Entactogen Pharmacology, and Receptor Mapping.
5-MeO-DiPT ("Foxy Methoxy") — an orally active substituted tryptamine developed by Alexander Shulgin producing intense somatic tactile enhancement; circulated in early 2000s pressed ecstasy tablets; see Ecstasy Pill Forensics and Historical Adulteration Trends.
6-APB (Benzofuran) — an entactogen and 5-HT2A psychedelic synthesized by David E. Nichols, bioisosterically replacing MDMA's methylenedioxy ring with a benzofuran; see David E Nichols, Entactogen Pharmacology, and Receptor Mapping.
69Ron — online ethnobotanical researcher on DMT-Nexus and Herbpedia who formulated the modern Oilahuasca enzyme-sequencing framework and the non-toxic food-grade d-limonene extraction ("DryTek"); see 69Ron and Oilahuasca Chemistry.

A

Acyl Migration — non-enzymatic intramolecular transesterification where a fatty acyl group spontaneously relocates from a secondary to primary position (e.g. 2-AG shifting into 1-AG); see Endocannabinoid Chemistry and 2-AG Metabolism.
Agonist — a molecule that binds a receptor and activates it, producing an effect. Most classic psychedelics are agonists (or partial agonists) at a particular serotonin receptor.
Allylbenzene — a plant phenylpropanoid with a terminal double bond (-CH2-CH=CH2); natural precursors to Shulgin's phenethylamines; see Shulgin Ten Essential Amphetamines and Metabolic Chemistry.
aMT (alpha-Methyltryptamine) — a long-acting stimulant and psychedelic tryptamine (Soviet antidepressant Indopan) whose optical isomers ((S) stimulant vs (R)) and legal history formed the basis of Shulgin's critique of the Analogue Act; see Isomers, the Analogue Act, and Forensic Chemistry.
Analogue Act (Federal Analogue Act of 1986) — a U.S. federal statute (21 U.S.C. § 813) treating unscheduled chemicals as Schedule I substances if they are "substantially similar" in structure and effect to a controlled substance and intended for human consumption; see Isomers, the Analogue Act, and Forensic Chemistry.
Antagonist — a molecule that binds a receptor but blocks it, preventing activation.
Afterglow — a mood/clarity aftereffect some people report in the hours or days after an experience, once the acute effects have passed.
Argyria — a permanent, irreversible bluish-slate skin and ocular discoloration caused by chronic ingestion of ionic silver, which deposits in tissues and undergoes solar photoreduction into elemental metallic particles; see Colloidal Metals, Electrochemistry, and Nanoparticles.

B

Bhasma (Swarna / Rajata) — traditional calcined herbo-metallic preparations of ancient Indian Rasa Shastra; modern TEM and XRD confirm they are 15–50 nm zero-valent metal nanoparticles capped with organic botanical ligands; see Rasa Shastra and Ancient Indian Nanochemistry.
Bioassay — testing a substance's effect by taking a measured dose and recording the result. Alexander Shulgin's careful, low-to-high self-bioassays are the method behind PIHKAL and TIHKAL.
Bioelectricity — endogenous transmembrane electrical potentials and ion fluxes regulating cellular morphogenesis, pattern memory, and gene expression; see Bioelectricity, Forensic Genomics, and Alchemical Transmutation.
Bad trip / challenging experience — a frightening or distressing episode during a psychedelic experience; harm-reduction practice reframes it as something to move through with calm support, not fight.
BZP (1-Benzylpiperazine) — a synthetic piperazine stimulant acting as a dopamine/norepinephrine releaser, widely combined with TFMPP in mid-2000s counterfeit party pills during the global safrole shortage; see Ecstasy Pill Forensics and Historical Adulteration Trends.

C

Capillary Electrophoresis (CE) — high-voltage electrical separation of DNA fragments in sub-millimeter fluid capillaries; powers Sanger sequencing and forensic STR fingerprinting; see Bioelectricity, Forensic Genomics, and Alchemical Transmutation.
Chocolate Chip Cookie Effect (Hot-Spot Hazard) — non-uniform crystallization and capillary concentration when liquid-diluted microgram compounds (fentanyl, synthetic cannabinoids, 25I-NBOMe) are sprayed onto plant matter or blended into pills, creating localized lethal overdoses adjacent to inactive doses; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.
Choline Transporter 1 (CHT1) — the high-affinity presynaptic $Na^+/Cl^-$-dependent symporter that pumps free choline into cholinergic neurons, serving as the rate-limiting step in acetylcholine synthesis; see Cholinergic Neurotransmission and Cholinesterase Inhibition.
Colloidal Metal — a liquid suspension of zero-valent metal nanoparticles (1–100 nm) exhibiting localized surface plasmon resonance and light scattering (Tyndall effect); see Colloidal Metals, Electrochemistry, and Nanoparticles.
Come-up / onset — the period as effects begin and build.
Contraindication — a condition or combination that makes a substance unsafe for a given person (e.g. certain medications, heart conditions, pregnancy). Checking contraindications is a core safety step.
Convalescent Plasma — antibody-rich blood plasma harvested from recovered individuals to confer immediate passive immunity, deployed against the 1918 flu, Junin virus, and SARS-CoV-2; see Virology, Antivenom Immunology, and Aromatic Antimicrobials.
Cross-tolerance — when tolerance to one substance also reduces the effect of a related one (common among classic psychedelics), so taking them close together does not "stack" the way people expect.
Cyclization (Intramolecular) — acid-catalyzed ring closure converting open-chain terpenes like CBD into closed pyran-ring cannabinoids like THC; see Cannabinoid Isomerization.
Cytochrome P450 (CYP450) — the primary hemoprotein monooxygenase enzyme superfamily in the liver and intestines responsible for drug clearance, bioactivation, and herb-drug interactions; see Cytochrome P450 System Inhibition and Induction.

D

David E. Nichols — Professor Emeritus at Purdue University and pioneer of psychedelic medicinal chemistry; coined "entactogen," synthesized the APBs (6-APB) and NBOMes, and mapped serotonin GPCR docking; see David E Nichols, Entactogen Pharmacology, and Receptor Mapping.
Deliriant — a class (e.g. certain anticholinergics) that produces confusion and true, often unpleasant, hallucinations; distinct from — and generally far riskier than — classic psychedelics.
Dissociative — a class (e.g. ketamine, DXM) that produces a sense of detachment from body/environment; a different mechanism from classic psychedelics.
Dose-response — the relationship between how much is taken and the effect; small differences in dose can mean large differences in experience, which is why start-low is the harm-reduction rule.
DPT (N,N-Dipropyltryptamine) — a potent synthetic psychedelic tryptamine utilized as the central holy sacrament ("the True Flesh of God") by the Temple of True Inner Light; see Religious Sacraments, RFRA, and the Temple of True Inner Light.
DryTek (d-Limonene Extraction) — a green-chemistry extraction technique developed by 69Ron using food-grade d-limonene and calcium hydroxide to extract freebase alkaloids without neurotoxic petroleum solvents; see 69Ron and Oilahuasca Chemistry.
Duration — total length of effects, from onset through comedown; recorded alongside dose for every compound.

E

Electroporation — applying brief, high-voltage electrical field pulses across cell membranes to create transient nanoscale pores for delivering CRISPR-Cas9, plasmids, and genetic cargo; see Bioelectricity, Forensic Genomics, and Alchemical Transmutation.
Endocannabinoidome (eCBome) — the expanded lipid-signaling complex encompassing classical cannabinoid receptors (CB1/CB2), alternative GPCRs (GPR55, GPR119), nuclear receptors (PPAR-α), TRPV1, and non-cannabinoid N-acylethanolamines (PEA, OEA); see The Expanded Endocannabinoid System and FAAH Science.
Endolysin — a phage-encoded peptidoglycan hydrolase ("enzybiotic") that rapidly lyses bacterial cell walls from within during viral burst or when applied exogenously against Gram-positive pathogens; see Bacteriophages Endolysins and Biological Inhibitors.
Entactogen / empathogen — a pharmacological class coined by David E. Nichols ("producing a touching within") describing compounds like MDMA and 6-APB that foster emotional openness, empathy, and social bonding distinct from classic hallucinogens; see David E Nichols, Entactogen Pharmacology, and Receptor Mapping.
Epoxidation — addition of an oxygen atom across an alkene double bond to yield a reactive three-membered oxirane ring, a key hepatic CYP450 detoxification and bioactivation pathway; see Universal Reaction Templates in Cannabinoid Chemistry.

F

Fab / F(ab')2 Fragment — pepsin-cleaved divalent or monovalent antibody fragments preserving antigen/toxin neutralization while removing the immunogenic Fc stalk, eliminating fatal serum sickness in antivenom therapy; see Virology, Antivenom Immunology, and Aromatic Antimicrobials.
Fentanyl Test Strip (FTS) — a lateral flow chromatographic immunoassay strip detecting fentanyl and major analogues down to 20–100 ng/mL; requires testing fully dissolved solutions to overcome hot-spot sampling errors; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.

H

HU-331 (Cannabidiol-Quinone) — a 1,4-benzoquinone oxidation product of CBD that acts as a selective, non-cardiotoxic catalytic inhibitor of DNA Topoisomerase IIα without CB1 receptor activity; see Cannabinoid Quinones and Novel Derivatives.

K

Ketene (CH2=C=O) — a highly reactive, toxic electrophilic gas released by thermal pyrolysis of acetate esters (THC-O-acetate, vitamin E acetate) above 200 °C; causes chemical pneumonitis and acute lung injury upon contact with alveolar moisture; see Cannabinoid and Tryptamine Prodrugs and Airway Irritation and Cannabinoid Prodrug Delivery.

M

Mace — the lacy crimson aril surrounding the nutmeg seed (Myristica fragrans); rich in elemicin with significantly less heavy trimyristin fat than the inner seed; see Allylbenzene Metabolism, Oswald Pathway, and Mace.
Main Protease (Mpro / 3CLpro) — the homodimeric cysteine protease of positive-sense single-stranded RNA viruses (including coronaviruses) essential for viral polyprotein cleavage, targeted by plant polyphenols like quercetin and EGCG; see Virology, Antivenom Immunology, and Aromatic Antimicrobials.
Mandelin Reagent — ammonium metavanadate in sulfuric acid; transition-metal vanadium redox reagent useful for ketamine (orange) and detecting toxic PMA/PMMA; see Colorimetric Reagents and Presumptive Chemical Testing.
MAOI (monoamine oxidase inhibitor) — a substance that blocks an enzyme which breaks down certain molecules. MAOIs can dangerously potentiate other drugs and foods and are a major source of interactions (the basis of ayahuasca's activity, and a serious contraindication with many medicines); see Monoamine Oxidase Inhibitors and Neurotransmitter Systems.
Marquis Reagent — concentrated sulfuric acid and formaldehyde; forms colored diarylmethane quinoid cations; turns dark purple/black with MDMA, orange/brown with amphetamines; see Colorimetric Reagents and Presumptive Chemical Testing.
Mechanism-Based Inactivation (MBI / Suicide Inhibition) — irreversible enzyme inhibition where an enzyme metabolizes a pseudosubstrate into a reactive electrophile that covalently destroys the catalytic heme or apoprotein; see Cytochrome P450 System Inhibition and Induction.
Mecke Reagent — selenious acid in sulfuric acid; selectively oxidizes catechol/dioxolane rings, flashing green to dark blue with MDMA; see Colorimetric Reagents and Presumptive Chemical Testing.
Mephedrone (4-MMC) — an intensely euphoric synthetic cathinone monoamine releaser that dominated European club scenes in the late 2000s; see Ecstasy Pill Forensics and Historical Adulteration Trends.
Methylone (bk-MDMA) — a $\beta$-keto synthetic cathinone analog of MDMA with shorter duration and higher dopamine release, widely substituted as counterfeit "Molly"; see Ecstasy Pill Forensics and Historical Adulteration Trends.
Microdose — a sub-perceptual dose (well below a felt threshold) taken on a schedule; evidence for benefits is mixed and still debated.
Molar Stoichiometry & Salt Factor — dosing based on molecular count ($6.022 \times 10^{23}$ molecules per mole) rather than gross weight; calculating active freebase from ionic salt masses (HCl, fumarate, tartrate) to prevent accidental under- or overdoses; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.

N

Naloxone (Narcan) — a pure competitive $\mu$-opioid receptor antagonist that rapidly displaces fentanyl and opioid agonists from receptors within 2–3 minutes, reversing life-threatening respiratory depression; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.
Nucleophile Trap — the failure mode of acid-catalyzed cannabinoid isomerization when conducted in polar protic solvents (like ethanol), where the solvent attacks the carbocation intermediate, forming inactive ethoxy-cannabinoid adducts instead of closing the pyran ring; see Solvent Chemistry and Polarity in Botanical Extraction.
N,O-TMS / α,N,O-TMS — in analytical chemistry, the silylation of protic hydrogens on amino and hydroxyl groups via BSTFA/BSA; in Shulgin's TIHKAL Entry #55, a chemical acronym for 5-methoxy-α,N-dimethyltryptamine and his "holy grail" 2-position indole SAR rule; see Structure-Activity Relationships in Psychopharmacology.

O

Oswald Pathway — the in vivo metabolic pathway (discovered by E.O. Oswald) wherein allylbenzenes are hydroxylated, oxidized to phenyl vinyl ketones, and conjugated with endogenous secondary amines (piperidine, dimethylamine) into tertiary amino-alkaloids; see Allylbenzene Metabolism, Oswald Pathway, and Mace.
Oxytocin — a hypothalamic nonapeptide neuropeptide governing trust, pair bonding, and social empathy, released centrally and peripherally via 5-HT1A/5-HT2C receptor stimulation by entactogens like MDMA and 5-MeO-DMT; see Structure-Activity Relationships in Psychopharmacology.

P

Paan — an ancient South Asian ceremonial masticatory combining areca nut (arecoline), slaked lime ($Ca(OH)_2$), betel leaf (eugenol), and spices, producing synergistic cholinergic and monoaminergic activation; see Traditional Spiced Formulations and Synergistic Blends.
Partition Coefficient (log P) — a physical chemistry measurement of lipophilicity determining how a molecule distributes between a non-polar solvent and water; CBD and THC have a highly hydrophobic log P of ~6.3; see Solvent Chemistry and Polarity in Botanical Extraction.
Phenethylamine — the chemical family at the center of PIHKAL (the 2C-x and DOx series, the mescaline and MDMA relatives).
Photoredox Catalysis — using visible light (blue LEDs) and transition-metal complexes to drive single-electron transfer (SET) reactions at room temperature without harsh acids; see Cannabinoid Photochemistry and Degradation.
Potentiation — one substance amplifying another's effect; can be intended or a hidden danger (see MAOI).
Presumptive Testing — rapid qualitative spot testing indicating the presence or absence of chemical functional groups, prone to adulterant masking; distinct from confirmatory chromatography (GC-MS/HPLC); see Colorimetric Reagents and Presumptive Chemical Testing.
Prodrug — a compound inactive until the body converts it into the active form (e.g. psilocybin → psilocin).
Propenylbenzene — a plant phenylpropanoid with a double bond directly conjugated with the aromatic ring (-CH=CH-CH3), existing as cis and trans geometric isomers; see Shulgin Ten Essential Amphetamines and Metabolic Chemistry.
Psychedelic (classic / serotonergic) — substances (e.g. LSD, psilocin, mescaline, DMT) that act mainly as agonists at the 5-HT2A serotonin receptor, producing changes in perception, thought, and mood.
Psychotropics Convention (1971) — the United Nations multilateral treaty establishing global controls and four scheduling tiers for synthetic psychedelics, stimulants, and sedatives; see Psychotropics Convention and the UDV Precedent.

Q

Quinone (Cannabinoid) — an oxidized aromatic dione derivative (such as HU-331 or VCE-003.2) that redirects cannabinoid targets from CB1 toward Topoisomerase IIα and PPARγ; see Cannabinoid Quinones and Novel Derivatives.

R

Rasa Shastra — classical Indian iatrochemistry and metallurgical pharmaceutics; transforming metals into biocompatible, non-toxic organo-metallic nanoparticles (Bhasmas) via cyclic calcination; see Rasa Shastra and Ancient Indian Nanochemistry.
Reagent testing — using chemical test kits (Marquis, Mecke, Simon's, etc.) to check what a substance actually is before use; a cornerstone of harm reduction because street material is frequently mis-sold.
Racemate / enantiomer — mirror-image forms of the same molecule; they can differ sharply in activity, a recurring theme in Shulgin's chemistry; see Stereochemistry in Cannabinoid and Psychedelic Synthesis.
RFRA (Religious Freedom Restoration Act of 1993) — federal statute restoring strict scrutiny for religious exercise burdened by federal law, under which the Supreme Court unanimously protected the sacramental use of Schedule I ayahuasca in Gonzales v. UDV; see Religious Sacraments, RFRA, and the Temple of True Inner Light.
RIMA (Reversible Inhibitor of MAO-A) — a reversible, competitive inhibitor of monoamine oxidase A (e.g. harmine, harmaline, moclobemide) that can be displaced by dietary tyramine, avoiding the hypertensive cheese crisis; see Monoamine Oxidase Inhibitors and Neurotransmitter Systems.

S

SALLE (Salting-Out Assisted Liquid-Liquid Extraction) — a purification technique using ice-cold saturated brine to halt reaction kinetics and sharpen phase separation between non-polar solvents and water; see Cannabinoid Isomerization.
Salt Shaker Metaphor — Alexander Shulgin's critique of the Federal Analogue Act: asking at what point a salt shaker with 5 holes becomes something else if you add or remove a hole, illustrating the vagueness of "substantial similarity"; see Isomers, the Analogue Act, and Forensic Chemistry.
Serine Hydrolase Superfamily — an extensive enzyme family (including FAAH, MAGL, AChE, and lipases) sharing an active serine nucleophile; see Enzyme Inhibition Kinetics and Molecular Transporters.
Serotonin Syndrome (Toxicity) — a potentially fatal hypermetabolic state caused by excessive synaptic serotonin overstimulating 5-HT2A/5-HT1A receptors, triggered by combining MAOIs/RIMAs with SSRIs, SNRIs, MDMA, or DXM; see Monoamine Oxidase Inhibitors and Neurotransmitter Systems.
Set and setting — one's mindset (mood, intention, expectations) and the physical/social environment. Widely held to shape an experience as much as the substance and dose.
Shulgin Rating Scale — Shulgin's qualitative intensity scale, from minus (no effect) through +, ++, +++ to the rare ++++ (a distinct peak/transcendent state); see PIHKAL and TIHKAL.
Simon's Reagent — sodium nitroprusside and acetaldehyde in alkaline carbonate buffer; reacts specifically with secondary amines (MDMA, methamphetamine) to form an intense cobalt blue complex; see Colorimetric Reagents and Presumptive Chemical Testing.
Spagyrics (Tria Prima) — Paracelsian alchemical pharmacy separating plants into Sulfur (essential oils/terpenes), Mercury (alcohol/active essence), and Salt (purified calcined mineral ash); see Bioelectricity, Forensic Genomics, and Alchemical Transmutation.
Strontium Mimicry — the ability of divalent strontium ($Sr^{2+}$) to substitute isomorphously for calcium ($Ca^{2+}$) in bone hydroxyapatite, enabling dual-action osteoblast stimulation / osteoclast inhibition (strontium ranelate) and driving Strontium-90 bone marrow beta radiation; see Alkaline Earth Metals, Calcium Signaling, and Strontium Mimicry.
Structure–activity relationship (SAR) — how small steric, electronic, and lipophilic changes to a molecule's structure redirect its affinity across receptors and enzymes; the systematic thread running through PIHKAL and TIHKAL; see Structure-Activity Relationships in Psychopharmacology.
Serotonergic — acting on the serotonin system; the mechanism of the classic psychedelics.

T

Temple of True Inner Light — a Manhattan religious congregation (rooted in the Native American Church) that openly used the synthetic tryptamine DPT as its central Eucharistic sacrament for decades; see Religious Sacraments, RFRA, and the Temple of True Inner Light.
Test dose / allergy dose — taking a small fraction first to check for a bad reaction before a full dose.
TFMPP (3-Trifluoromethylphenylpiperazine) — a non-selective serotonin receptor agonist combined with BZP in mid-2000s party pills to mimic MDMA, causing severe migraines and nausea; see Ecstasy Pill Forensics and Historical Adulteration Trends.
Threshold dose — the smallest amount at which any effect is felt (the "±" on the scale).
Tolerance — reduced effect from repeated use, so more is needed for the same result; for classic psychedelics it builds fast and fades after a break.
Tripsitter — a sober, trusted person who stays present to keep someone safe and grounded during an experience.
Tryptamine — the chemical family at the center of TIHKAL (DMT and relatives, the psilocin group).
Tyramine Hypertensive Crisis ("Cheese Effect") — severe, life-threatening blood pressure spike caused by consuming aged tyramine-rich foods during irreversible MAO-A inhibition; see Monoamine Oxidase Inhibitors and Neurotransmitter Systems.

U

UDV Precedent (Gonzales v. UDV, 2006) — unanimous Supreme Court ruling establishing that RFRA protects the sacramental importation and consumption of hoasca (ayahuasca/DMT), decisively rejecting the DEA's international treaty defense under the 1971 Psychotropics Convention; see Psychotropics Convention and the UDV Precedent.

V

Voltage-Gated Calcium Channels (VGCCs) — high-voltage-activated presynaptic channels (Cav2.1, Cav2.2) mediating calcium influx that triggers neurotransmitter exocytosis, directly inhibited by retrograde endocannabinoid CB1 activation; see Alkaline Earth Metals, Calcium Signaling, and Strontium Mimicry.
Volumetric Liquid Dosing (VLD) — dissolving a known mass of powder into a measured volume of liquid to achieve microgram-accurate oral syringe dosing, eliminating the deadly error of eyeballing powders; see Molar Stoichiometry, Powder Density, and Tolerance Kinetics.

Z

Zinc Ionophore — a lipophilic molecule (such as the flavonoid quercetin) that binds divalent zinc ($Zn^{2+}$) to transport it across hydrophobic cellular membranes, elevating intracellular zinc to inhibit viral RNA-dependent RNA polymerase (RdRp); see Virology, Antivenom Immunology, and Aromatic Antimicrobials.

Sources

Terminology reflects standard pharmacology and harm-reduction practice; compound-specific data and the rating scale trace to A. & A. Shulgin's PIHKAL and TIHKAL, with full entries hosted at Erowid.

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