Meet the Compound: Coenzyme Q10

coq10Molecular Formula: C59H90O4

Molecular Weight: 863.34 g/mol

Mechanism of Action: CoQ10 occurs naturally in the body, an important antioxidant in the mitochondrial electron transport chain1. It has been shown to decrease the abnormally high lactate-pyruvate levels in cerebrospinal fluid in HD2.

CoQ10 has been explored as a neuroprotective in PD and HD (Table 1). Although the QE3 trial of CoQ10 in PD showed no significant benefits,3 studies in HD have shown more promising results. Dr. Flint Beal, Professor of Neurology and Neuroscience at Weill Medical College of Cornell University, told HD Insights that the failure of CoQ10 in PD has an unknown impact on its use in HD. “I am still hoping that the results in HD will be beneficial,” he said. Dr. Karl Kieburtz, Director of the Clinical and Translational Science Institute at the University of Rochester, told HD Insights that the evidence for a modest benefit of CoQ10 in HD is greater than in the case of PD. The CARE-HD study of high dose CoQ10 and remacemide in HD demonstrated a trend toward slowing functional decline4. Dr. Kieburtz suggested that these results may indicate that the benefits of long-term CoQ10 are detectable only in a clinical trial setting. Further exploration of CoQ10 is important, he said, because it is a low-cost, readily available intervention that people at risk for HD can take at low risk for a long time, while some more potent therapies that target specific biological processes may demonstrate high toxicities. This exploration is currently being undertaken in the 2CARE study, a multi-center, randomized, double-blind, placebo-controlled study of high-dose CoQ10, conducted by the Huntington Study Group (HSG) under the direction of Drs. Merit Cudkowicz, Michael McDermott, and Karl Kieburtz. 2CARE aims to identify the effects of CoQ10 on functional decline in HD, as well as its long-term safety and tolerability5.

coq10 table

The PREQUEL study represents the first randomized, controlled trial of CoQ10 in premanifest HD, under the direction of Drs. Christopher Ross of Johns Hopkins University, and Kevin Biglan of the University of Rochester. The results of PREQUEL will be presented at this year’s HD Clinical Research Symposium. Dr. Ralf Reilmann (see “Selected by Chance,” p. 1) said, “I think PREQUEL is one of the most fantastic studies. This was a proof-of-concept study, and I think we are transitioning from a phase where such trials were unrealistic, to a phase where we can actually consider doing challenging, disease-modifying trials in both manifest HD and premanifest HD.”


1 Chaturvedi RK, Beal MF. Mitochondria targeted therapeutic approaches in Parkinson’s and Huntington’s diseases. Mol Cell Neurosci. 2013 Jul; 55:101-14.

2 Koroshetz WJ, Jenkins BG, Rosen BR, Beal MF. Energy metabolism defects in Huntington’s disease and effects of coenzyme Q10. Ann. neurol. 1997;41(2):160-5. Epub 1997/02/01. doi: 10.1002/ana 410410206. PubMed PMID: 9029064.

3 National Institute of Neurological Disorders and Stroke (NINDS). Statement on the termination of QE3 study [Internet]. [Updated 2011 June 2; cited 2013 Sep 19]. Available from

4 Kieburtz K, Koroshetz W, McDermott M, et al. A randomized, placebo-controlled trial of coenzyme Q10 and remacemide in Huntington’s disease. Neurol. 2001 Aug 14; 57(3):397-404.

5 Coenzyme Q10 in Huntington’s Disease (HD) (2CARE) [Internet]. [Cited 2013 Sep 19]. Available from +Huntington&rank=1.

6 Hyson HC, Kieburtz K, Shoulson I, et al. Safety and tolerability of high-dosage coenzyme Q10 in Huntington’s disease and healthy subjects. Mov Disord. 2010;25(12):1924-8.

7 Schults CW, Oakes D, Kieburtz K, et al. Effects of coenzyme Q10 in early Parkinson d isease: Evidence of slowing of the functional decline. Arch Neurol. 2002 Oct; 59(10):1541-50.

8 Kieburtz K, Ravina B, Galpern W, et al. A randomized clinical trial of coenzyme Q10 and GPI-1485 in early Parkinson Disease. Neurol. 2007 Jan 2;68(1):20-28.

9 Beal MF. A phase III clinical trial of coenzyme Q10 (QE3) in early Parkinson’s disease: Parkinson Study Group QE3 Investigators [Abstract]. Mov Disord. 2012 Jun 17-21; 27 Suppl 1:346.