Does PBO Inhibit Metabolizing Enzymes in Humans?

Limited human studies with PBO were conducted over 40 years ago by the pharmaceutical industry to see if PBO could be used to slow the metabolism of pharmaceuticals in humans, thereby prolonging their effectiveness.  They showed no effect of PBO on human metabolism of pharmaceuticals (Conney, 1972).

PBO has been used extensively in toxicology and pharmacology as a research tool to inhibit the Mixed Function Oxidase System (MFOS)-mediated metabolism by a wide variety of mammals.  The doses used in such research were usually quite large (often as high as 600 mg/kg) and were usually administered via intraperitoneal injection (injection directly into the abdomen).

The dose levels used in these studies are far in excess of what humans would ever be expected to encounter and are through an exposure route which is not relevant to humans (intraperitoneal injection).  Incidental exposures encountered by humans when using consumer products are magnitudes lower than those used in this kind of research.