SR-17018

SR-17018
Clinical data
Other names	SR17018; SR-17; SR17; SR
Drug class	μ-Opioid receptor biased partial agonist; Analgesic; Opioid replacement
Pharmacokinetic data
Onset of action	1–2 hours
Identifiers
	IUPAC name 5,6-dichloro-3-[1-[(4-chlorophenyl)methyl]piperidin-4-yl]-1H-benzimidazol-2-one;
CAS Number	2134602-45-0 ;
PubChem CID	130431397;
ChemSpider	67886365;
UNII	2M8P7UAW4W;
ChEMBL	ChEMBL4452384;
PDB ligand	WH9 (PDBe, RCSB PDB);
CompTox Dashboard (EPA)	DTXSID101336689 ;
Chemical and physical data
Formula	C19H18Cl3N3O
Molar mass	410.72 g·mol−1
3D model (JSmol)	Interactive image;
	SMILES C1CN(CCC1N2C3=CC(=C(C=C3NC2=O)Cl)Cl)CC4=CC=C(C=C4)Cl;
	InChI InChI=1S/C19H18Cl3N3O/c20-13-3-1-12(2-4-13)11-24-7-5-14(6-8-24)25-18-10-16(22)15(21)9-17(18)23-19(25)26/h1-4,9-10,14H,5-8,11H2,(H,23,26); Key:LAGUDYUGRSQDKS-UHFFFAOYSA-N;

SR-17018, also known informally as SR-17 or just SR, is an atypical opioid receptor modulator with unusual actions and effects. It acts as a biased partial agonist of the μ-opioid receptor (MOR), showing strong selectivity for activation of G protein signaling over β-arrestin2 recruitment.

Unlike conventional opioids such as morphine and fentanyl, SR-17018 produces robust analgesic effects in rodents with very little respiratory depression and with much less analgesic tolerance. Moreover, substitution of conventional opioids like morphine with SR-17018 can reverse analgesic tolerance and suppress withdrawal symptoms in rodents. However, conflicting findings exist in terms of analgesic tolerance and respiratory depression. The drug has not been formally studied in humans. implying an unknown safety profile.

SR-17018 was first described in the scientific literature by Laura Bohn and colleagues in 2017. It was encountered online as a novel designer drug by 2023. Subsequently, discussion of SR-17018 on the social media website Reddit dramatically increased in 2024. Although technically a designer opioid, SR-17018 is said to have very different effects from other opioids, for instance producing minimal euphoria. Rather than being used recreationally itself, SR-17018 is typically employed by users to prevent opioid withdrawal symptoms and facilitate opioid discontinuation in the context of opioid dependence.