A certified reference solution suitable for use as an internal standard for quantitation of O-desmethylvenlafaxine levels in urine or isotope dilution methods by LC/MS or GC/MS for clinical toxicology, urine drug testing, or forensic analysis.

Also known as desvenlafaxine, O-desmethylvenlafaxine is an SNRI antidepressant marketed under the trade name Pristiq® for treatment of depression. O-desmethylvenlafaxine is also a major urinary metabolite of venlafaxine, an SNRI antidepressant sold as Effexor® or Efexor and used to treat major depressive disorder, generalised anxiety disorder, and other anxiety disorders associated with depression.