O-Desmethyltramadol (O-DSMT)


O-Desmethyltramadol (O-DSMT) is an opioid which has primarily been used indirectly due to it being a primary metabolite of the analgesic tramadol. Since the 2010s it has occasionally been used on its own as it has been sold through the grey market/research chemical drug market.

It has a longer duration than tramadol and more typical opioid-like effects, although it still impacts monoaminergic systems to an extent that seems to influence the effect profile.

O-Desmethyltramadol = O-DSMT; Desmetramadol; O-Demethyltramadol

PubChem: 9838803

Molecular formula: C15H23NO2

Molecular weight: 249.354 g/mol

IUPAC: 3-[2-[(dimethylamino)methyl]-1-hydroxycyclohexyl]phenol




Experience Reports







Legality (As of October 2018)




Arndt, T., Claussen, U., Güssregen, B., Schröfel, S., Stürzer, B., Werle, A., & Wolf, G. (2011). Kratom alkaloids and O-desmethyltramadol in urine of a “Krypton” herbal mixture consumer. Forensic Science International, 208(1–3), 47–52. https://doi.org/10.1016/j.forsciint.2010.10.025

Bäckberg, M., Jönsson, K. H., Beck, O., & Helander, A. (2018). Investigation of drug products received for analysis in the Swedish STRIDA project on new psychoactive substances. Drug Testing and Analysis, 10(2), 340–349. https://doi.org/10.1002/dta.2226

Dresen, S., Ferreirós, N., Pütz, M., Westphal, F., Zimmermann, R., & Auwärter, V. (2010). Monitoring of herbal mixtures potentially containing synthetic cannabinoids as psychoactive compounds. Journal of Mass Spectrometry, 45(10), 1186–1194. https://doi.org/10.1002/jms.1811

Helander, A., Beck, O., Hägerkvist, R., & Hultén, P. (2013). Identification of novel psychoactive drug use in Sweden based on laboratory analysis-initial experiences from the STRIDA project. Scandinavian Journal of Clinical and Laboratory Investigation, 73(5), 400–406. https://doi.org/10.3109/00365513.2013.793817

Horishita, T., Minami, K., Uezono, Y., Shiraishi, M., Ogata, J., Okamoto, T., & Shigematsu, A. (2006). The tramadol metabolite, O-Desmethyl tramadol, inhibits 5-hydroxytryptamine type 2C receptors expressed in Xenopus oocytes. Pharmacology, 77(2), 93–99. https://doi.org/10.1159/000093179

Kronstrand, R., Roman, M., Thelander, G., & Eriksson, A. (2011). Unintentional fatal intoxications with mitragynine and o-desmethyltramadol from the herbal blend krypton. Journal of Analytical Toxicology, 35(4), 242–247. https://doi.org/10.1093/anatox/35.4.242

Matic, M., De Wildt, S. N., Elens, L., De Hoon, J. N., Annaert, P., Tibboel, D., … Allegaert, K. (2016). SLC22A1 /OCT1 Genotype Affects O-desmethyltramadol Exposure in Newborn Infants. Therapeutic Drug Monitoring, 38(4), 487–492. https://doi.org/10.1097/FTD.0000000000000307

Minami, K., Yokoyama, T., Ogata, J., & Uezono, Y. (2011). The Tramadol Metabolite O-Desmethyl Tramadol Inhibits Substance P– Receptor Functions Expressed in Xenopus Oocytes. Journal of Pharmacological Sciences J Pharmacol Sci, 115, 421–424. https://doi.org/10.1254/jphs.10313SC

Nakamura, M., Minami, K., Uezono, Y., Horishita, T., Ogata, J., Shiraishi, M., … Sata, T. (2005). The effects of the tramadol metabolite O-desmethyl tramadol on muscarinic receptor-induced responses in Xenopus oocytes expressing cloned M1or M3receptors. Anesthesia and Analgesia, 101(1), 180–186. https://doi.org/10.1213/01.ANE.0000154303.93909.A3

Sevcik, J., Nieber, K., Driessen, B., & Illes, P. (1993). Effects of the central analgesic tramadol and its main metabolite, O‐desmethyltramadol, on rat locus coeruleus neurones. British Journal of Pharmacology, 110(1), 169–176. https://doi.org/10.1111/j.1476-5381.1993.tb13788.x

Valle, M., Garrido, M. J., Pavon, J. M., Calvo, R., & Troconiz, I. F. (2000). Pharmacokinetic-pharmacodynamic modeling of the antinociceptive effects of main active metabolites of tramadol, (+)-O-desmethyltramadol and (-)-O-desmethyltramadol, in rats. J Pharmacol Exp Ther.