A-836,339.

A-836,339 is a cannabinoid receptor agonist that is highly selective for CB2: 0.64 nanomoles per litre of affinity at the human CB2 against 270 at CB1, a ratio of about 420, confirmed in the rat. This selectivity concerns binding and does not rule out a central effect: effects mediated by CB1, measured in the rodent by a fall in spontaneous locomotor activity at a higher dose and by an activation pattern visible on pharmacological magnetic resonance imaging, appear as soon as exposure increases. THC is a partial agonist whose response plateaus; the high-efficacy agonists of the synthetic cannabinoid class know no such ceiling, which explains the severity peculiar to their poisonings, but the intrinsic efficacy of A-836,339 is not quantified in the sources consulted. What the literature establishes is confined to the animal model: an antihyperalgesic effect in inflammation induced by complete Freund's adjuvant, blocked by a CB2 antagonist and independent of CB1 and of mu opioid receptors, efficacy in chronic constriction of the sciatic nerve without tolerance after five days of treatment, and modulation of spinal wide dynamic range neurons in the neuropathic rat. What the literature does not establish is equally clear: no human data, no metabolism study, no published clinical case, and no documented action on TRPV1, GPR55, PPAR gamma or 5-HT1A.

Source

A wholly synthetic molecule, absent from hemp and from every living organism. It was designed by the pharmaceutical industry as a selective probe for the CB2 receptor, then taken up by medical imaging research: its carbon-11 labelled version served as an experimental radioligand for positron emission tomography in the rodent, and several fluorinated analogues have been built on its scaffold. The documented report outside the laboratory concerns a "dubious product" analysed by a Tokyo laboratory (Uemura et al.), which the authors present as the first such case for this substance.

No biosynthetic pathway: the molecule derives from no plant or animal metabolism and possesses no natural precursor. It belongs exclusively to synthetic chemistry.

European Union

No control at Union level: the substance does not appear in the annex to Framework Decision 2004/757/JHA, whose consolidated version of 12 January 2026 retains only a small number of synthetic cannabinoid agonists. It is likewise absent from the Green List of the International Narcotics Control Board, which records the substances placed under the regime of the 1971 Convention: no international control measure applies to it, and no critical review by the World Health Organization has been devoted to it. Scheduling is therefore a matter for each Member State, and France has chosen to name it.

France

The position is clear and rests on no generic clause: A-836,339 is listed by name on the French narcotics schedule. It appears in annex IV of the decree of 22 February 1990, under the heading of cannabinoids scheduled together with their isomers, stereoisomers, esters, ethers and salts, where the consolidated list published by the ANSM carries it under its code and under its full systematic name; it was entered there by the decree of 31 March 2017 (JORF of 6 April 2017). This is therefore not the case of the esters and ethers of THC, captured by a generic definition: the substance is cited in its own right. Production, possession, transfer and use fall under the criminal regime for narcotics, and no legal CBD product may contain it.

Sources: EUR-Lex, UNODC, CND, ANSM, IUPHAR/BPS, ChEBI, EUDA. Our method.

Family

Synthetic CB receptor agonist › Research ligand or medicine

Class

iminothiazoline carboxamide (tetramethylcyclopropane), outside the indole and indazole series

Verification

Classification, sources and binding values checked on 20 October 2026; text read against its sources and Wikipedia.

Wikipedia (English)

A-836,339 (new tab)

Article paired by the molecule's structure (InChIKey), revision read on 19 October 2026. Read as a second opinion, never cited as a source.

1. 1Yao BB et al., Journal of Pharmacology and Experimental Therapeutics, 2009: characterisation of the selective CB2 agonist A-836339 in in vitro pharmacology, in vivo pain models and pharmacological MRI (human Ki values taken via ChEMBL and the later literature; full text not consulted) (new tab)PMID 18931146
2. 2Horti AG et al., Bioorganic and Medicinal Chemistry, 2010: synthesis and biodistribution of [11C]A-836339, a candidate radioligand for PET imaging of CB2 receptors (new tab)PMID 20554448
3. 3McGaraughty S et al., Neuroscience, 2009: A-836,339 modulates the activity of spinal wide dynamic range neurons in the neuropathic rat (new tab)PMID 19063946
4. 4Hsieh GC et al., British Journal of Pharmacology, 2011: central and peripheral sites of action of CB2-mediated analgesia in the rat, with A-836,339 and AM1241 (new tab)PMID 20880025
5. 5Pottier G et al., Journal of Cerebral Blood Flow and Metabolism, 2017: [11C]A-836339 does not reveal any change in CB2 receptors after neuroinflammation in the rat (new tab)PMID 28079433
6. 6Uemura N et al., Forensic Toxicology, 2014, volume 32, pages 45 to 50: identification of A-836,339 as a novel compound found in a dubious product (Tokyo Metropolitan Institute of Public Health) (new tab)DOI 10.1007/s11419-013-0201-x
7. 7Caillé F et al., Molecular Pharmaceutics, 2017: structure-activity relationships on thiazole derivatives and microsomal metabolism of a fluorinated analogue of A-836,339 (data for the analogue, not for the parent molecule) (new tab)PMID 28968497
8. 8ANSM, consolidated list of substances classified as narcotics, updated 16 February 2026: A-836,339 named in Annex IV of the order of 22 February 1990 (new tab)
9. 9Council Framework Decision 2004/757/JHA, consolidated version of 12 January 2026, annex of substances subject to control measures in the Union (new tab)
10. 10International Narcotics Control Board, Green List of psychotropic substances under the control of the 1971 Convention, 2026 edition (new tab)
11. 11PubChem, record of compound CID 17754357 (A-836,339) (new tab)
12. 12Order of 31 March 2017 amending the order of 22 February 1990 setting the list of substances classified as narcotics (Légifrance, JORF of 6 April 2017): A-836,339 named in Annex IV (new tab)

SMILES

CC1=C(SC(=NC(=O)C2C(C2(C)C)(C)C)N1CCOC)C

Machine-readable entry (JSON)

LLM ingestion format: a structured superset of the entry (identifiers, binding, versioned legal status). Full corpus.