Coenzyme Q10 be measured in blood plasma, these measurements reflect dietary intake rather than tissue status. Currently, most clinical centers measure CoQ levels in cultured skin fibroblasts, muscle biopsies, and blood mononuclear cells. Culture fibroblasts can be used also to evaluate the rate of endogenous CoQ biosynthesis, by measuring the uptake of C-labelled "p"-hydroxybenzoate. CoQ shares a biosynthetic pathway with cholesterol. The synthesis of an intermediary precursor of CoQ, mevalonate, is inhibited by some beta blockers, blood pressure-lowering medication, and statins, a class of cholesterol-lowering drugs. Statins can reduce serum levels of CoQ by up to 40%. CoQ is not approved by
Blood doping at the Australian Defence Science and Technology Organization Chris Forbes-Ewan is quoted as saying that, unlike in sport, "all's fair in love and war." "What we are trying to gain is an advantage over any potential adversary," Forbes-Ewan said. In this study, over 50 performance-enhancing drugs and techniques were rejected. The six that were approved are caffeine, ephedrine, energy drinks, modafinil, creatine, and blood-loading. Blood doping started in the late 1960s but was not outlawed until 1986. While it was still legal, it was commonly used by middle and long-distance runners. The first known case of blood doping occurred at