{"schemaVersion":"cwiki-fiche-1.0","identifiers":{"inchiKey":"NUXUDGMVYZUFNQ-NXRUOVBSSA-N","prefName":"Isotetrahydrocannabinol","symbol":"iso-THC","iupacName":"(1R,12R)-9-methyl-5-pentyl-12-prop-1-en-2-yl-8-oxatricyclo[7.3.1.0²,⁷]trideca-2,4,6-trien-3-ol","aliases":["isotetrahydrocannabinol","iso-THC","Δ8-iso-THC","isotétrahydrocannabinol"],"cas":null,"pubchemCid":"176804934","chebiId":null,"smiles":"CCCCCC1=CC(=C2[C@@H]3CC(CC[C@H]3C(=C)C)(OC2=C1)C)O","molecularFormula":"C21H30O2","molecularWeight":314.5,"xrefs":{"pubchem":"https://pubchem.ncbi.nlm.nih.gov/compound/176804934"}},"classification":{"family":"semisynthetique","familyLabel":"Semi-synthetic cannabinoid","origin":"semisynthetic","originLabel":"Semi-synthétique","structuralClassFr":"Squelette iso-THC : système oxatricyclique ponté, formellement isomère du tétrahydrocannabinol dont il partage la formule brute sans en partager l'ossature. Là où le THC présente un enchaînement benzo[c]chromène linéaire, l'iso-THC referme le pont oxygéné sur un carbone différent, ce qui déplace la chaîne isopropényle et modifie la géométrie d'ensemble. Le même squelette se retrouve dans le cannabiglendol, cannabinoïde de traces à chaîne propyle, dont la pharmacologie n'est pas davantage documentée."},"originSynthesis":{"heading":"Route of preparation (chemical process)","summaryFr":"No known plant enzymatic route for this isomer. It forms by intramolecular cyclisation of cannabidiol in acid medium: addition of the phenol onto one of the two double bonds of cannabidiol determines the skeleton obtained, and attack of the Δ1 double bond leads to the iso-THC framework instead of the benzo[c]chromene of THC. The molecule is described here by chemical class only.","originNote":"A conversion compound, formed during the acid cyclisation of cannabidiol. It is not described as a notable natural constituent of hemp: it is encountered above all as a by-product in preparations obtained by isomerisation of cannabidiol, a channel that has become massive since cannabidiol-rich hemp began to be produced in surplus.","discovered":"Les isomères iso-THC apparaissent dans l'étude de la cyclisation intramoléculaire du cannabidiol en milieu acide, réaction qui produit principalement le Δ9-THC et le Δ8-THC. Kiselak et collaborateurs, en 2020 dans le Journal of Natural Products, ont établi que lorsque l'activation porte sur la double liaison Δ1 du cannabidiol plutôt que sur la double liaison Δ8, la cyclisation conduit au squelette iso-THC. Cette voie est nettement moins fréquente que la voie principale, et les isomères correspondants ont reçu très peu d'attention."},"pharmacology":{"summaryFr":"Isotetrahydrocannabinol denotes a family of isomers arising from the intramolecular cyclisation of cannabidiol in acid medium, a reaction used industrially to convert hemp cannabidiol into Δ8-THC or Δ9-THC. Kiselak and colleagues (2020) showed that the nature of the product depends on which double bond is attacked: activation of the Δ8 double bond gives the expected tetrahydrocannabinols, that of the Δ1 double bond leads to the iso-THC skeleton, a minority route. The result is not a tetrahydrocannabinol in the structural sense: the characteristic benzo[c]chromene ring is replaced by a bridged oxatricyclic system, and the molecule thus falls outside the template to which cannabinoid receptors respond. No affinity or activity data have been published for this compound, and this entry refrains from assuming any. Its practical interest lies elsewhere: the iso-THC isomers are among the by-products that acid isomerisation leaves in preparations, alongside other impurities, and their presence serves as a marker of the process used.","receptorSummaryFr":"No affinity or efficacy value has been published for CB1 or for CB2. The structural argument calls for caution rather than extrapolation: the iso-THC skeleton is not a benzo[c]chromene but a bridged oxatricyclic system, in which the geometry of the classical cannabinoid pharmacophore is not preserved. In the absence of measurement, no activity can be asserted, and the values given here are a signal of absent data, not an estimate.","binding":[{"target":"CB1","efficacy":"partial_agonist","relativeActivity":3,"reported":null,"confidence":"low"},{"target":"CB2","efficacy":"partial_agonist","relativeActivity":3,"reported":null,"confidence":"low"}],"references":[{"label":"Kiselak et coll. 2020 : le cannabidiol comme substrat de cyclisation intramoléculaire acide","pmid":"32991167","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/32991167/"},{"label":"PubChem CID 176804934 : isotétrahydrocannabinol","pmid":null,"doi":null,"url":"https://pubchem.ncbi.nlm.nih.gov/compound/176804934"}]},"pharmacokinetics":"Aucune donnée. Le composé n'a fait l'objet d'aucune étude d'absorption, de distribution ou d'élimination, chez l'animal comme chez l'humain. Sa présence dans les produits de conversion du cannabidiol signifie qu'il est ingéré ou inhalé avec eux, sans que l'exposition correspondante ait jamais été quantifiée.","metabolism":"Aucune étude de métabolisme n'est publiée. La fonction phénol libre offre un site de glucuronidation directe, et la chaîne pentyle un site d'oxydation, par analogie avec les cannabinoïdes classiques ; ces attentes de classe ne reposent sur aucune observation propre à ce composé.","detection":"Recherché en analyse de produits plutôt qu'en toxicologie clinique. Sa présence, à côté d'autres sous-produits, permet aux laboratoires de reconstituer le procédé d'obtention d'un échantillon de Δ8-THC ou de Δ9-THC et de distinguer une origine par conversion d'une origine végétale. Aucun immunoessai ne le cible.","subjectiveEffects":{"profile":[{"key":"calm","label":"Calm","description":"Relaxation of body and mind; reduced mental noise without marked drowsiness.","intensity":5},{"key":"focus","label":"Clarity","description":"Sustained attention and clear thinking; functional lucidity, not euphoria.","intensity":5},{"key":"sleep","label":"Sleep","description":"Sedative effect: aids sleep onset and the continuity of deep sleep.","intensity":5},{"key":"appetite","label":"Appetite","description":"Stimulation of hunger and of taste appreciation (the “munchies” effect).","intensity":5},{"key":"uplift","label":"High","description":"Euphoria and sensory intensity; altered perception of time and space.","intensity":5}],"doseRanges":null,"humanDataCharacterised":true},"indications":{"approvedMedicines":[]},"harmProfile":{"unstudiedBanner":false,"bannerTextFr":null,"toxicologyFr":"Aucune donnée de toxicologie. La question pertinente est celle des produits d'isomérisation du cannabidiol pris dans leur ensemble, dont plusieurs analyses ont montré qu'ils contiennent des impuretés en concentrations très supérieures à ce que déclarent les certificats d'analyse. L'iso-THC est l'une de ces impuretés parmi d'autres, et son innocuité n'est ni établie ni infirmée."},"legal":{"scheduleStatus":"unscheduled","scheduleLabel":"Unscheduled","frScheduleStatus":"unscheduled","tiers":[{"jurisdiction":"international","jurisdictionLabel":"International","label":null,"reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null},{"jurisdiction":"eu","jurisdictionLabel":"Union européenne","label":"No harmonised control at Union level and no listing under the international conventions of 1961 and 1971. The molecule is treated above all as an analytical marker of cannabidiol isomerisation processes, a question belonging to product safety more than to narcotics law.","reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null},{"jurisdiction":"fr","jurisdictionLabel":"France","label":"The substance is named in no French text. Annex IV of the arrêté of 22 February 1990 classifies as narcotics the tetrahydrocannabinols, their esters, their ethers and their salts: isotetrahydrocannabinol, whose bridged oxatricyclic skeleton is not that of a tetrahydrocannabinol, does not fall directly under that heading. Its presence as an impurity in a product arising from the isomerisation of cannabidiol nonetheless leaves that product subject to the law applicable to its main constituent.","reference":null,"url":null,"effectiveDate":null,"lastVerified":"2026-05-01","supersededBy":null}],"sourcesFr":"EUR-Lex, UNODC, CND, ANSM, IUPHAR/BPS, ChEBI, EUDA."},"references":[{"label":"Kiselak et coll. 2020 : le cannabidiol comme substrat de cyclisation intramoléculaire acide","pmid":"32991167","doi":null,"url":"https://pubmed.ncbi.nlm.nih.gov/32991167/"},{"label":"PubChem CID 176804934 : isotétrahydrocannabinol","pmid":null,"doi":null,"url":"https://pubchem.ncbi.nlm.nih.gov/compound/176804934"}],"meta":{"slug":"iso-thc","url":"https://en.phytogrammes.com/wiki/iso-thc","lastVerified":"2026-05-01","dataUpdatedAt":"2026-08-14","confidence":"medium","dataCompletenessPct":80,"disclaimerFr":"Contenu éditorial informatif, sans valeur d'avis médical ni juridique. Sources primaires citées par fiche. Réservé aux adultes."}}