In our previous blog “Ubiquinol and Your Heart: The Cellular Story,” we discussed the role of Ubiquinol, the active antioxidant form of coenzyme Q10, in energy production and heart health. Given its critical role, it is important to understand its bioavailability and pharmacokinetics to aid in proper clinical use.
As you may know, coenzyme Q10 in its basic form is not highly absorbable in the body. But studies suggest that Ubiquinol has superior absorption and can replenish the normal CoQ10 plasma concentration. In a randomized, double-blind, crossover study, the bioavailability of Ubiquinol and coenzyme Q10 were compared using an acute intake of 100 mg in 10 healthy subjects with 2 weeks between treatments. Plasma concentrations were significantly higher for Ubiquinol compared to coenzyme Q10 at 6, 8, 12, 24, 48, and 72 hours post-intake (P<0.001) and the AUC for Ubiquinol 72 hours post-intake was 4.3-fold greater than for coenzyme Q10.1
This greater bioavailability was also shown for chronic intake. In a crossover, comparative study in 12 healthy subjects, uptake of Ubiquinol and coenzyme Q10 (200 mg/d) were compared after four weeks of supplementation. Ubiquinol was absorbed over two times as well as ubiquinone in direct comparison (P<0.005). When comparing final plasma concentrations, Ubiquinol was absorbed 1.7 times more than CoQ10 (4.3 µg/ml vs. 2.5 µg/mL), or 70% better.2 A possible mechanism for this is increased micellarization in the gut, because the reduced nature of Ubiquinol facilitates micelle formation, a necessary step in absorption in the small intestine.3
The amount of absorption will vary based on a person's age and state of health, but in every published comparative study that has been done, Ubiquinol has consistently been much better absorbed than coenzyme Q10 and replenishes the plasma concentration.1,2,4-8
Along with bioavailability, transportability in the blood to the sites of use is a key factor in efficacy. Ubiquinol is transported in the blood by attaching to lipid low density lipoprotein cholesterol (LDL cholesterol) particles. If coenzyme Q10 is ingested, the body quickly transforms it into Ubiquinol via an enzymatic reaction, making it the form that is most preferred by the body for transport in the blood.6 Some people cannot perform that transition very efficiently, and therefore receive very little benefit if they take coenzyme Q10 as opposed to Ubiquinol (look for a future blog on this topic!). However, in a healthy adult, more than 95% of the total coenzyme Q10 in the blood is in the Ubiquinol form.9-11 A major portion of CoQ10 in tissues is also in the reduced form as Ubiquinol.10
CoQ10 has a Tmax of 6.5 h and an elimination half-life of 33.19 h, meaning that once-a-day dosing is sufficient. Chronic administration produces a dose-dependent increase in plasma total Coenzyme Q10.12
- Evans M, Baisley J, Barss S, Guthrie N. A randomized, double-blind trial on the bioavailability of two CoQ10 formulations. Journal of Functional Foods. 2009. 1: 65-73.
- Langsjoen PH and Langsjoen AM. Comparison study of plasma coenzyme Q10 levels in healthy subjects supplemented with ubiquinol versus ubiquinone. Clinical Pharmacol Drug Dev. 2014;3(1):13-17.
- Failla ML, Chitchumroonchokchai C, Aoki F. Increased bioavailability of ubiquinol compared to that of ubiquinone is due to more efficient micellarization during digestion and greater GSH-dependent uptake and basolateral secretion by Caco-2 cells. J Agric Food Chem. 2014 Jul 23;62(29):7174-82.
- Miles MV, Horn P, Milesc L, Tanga P, Steele P, DeGrauwa T. Bioequivalence of coenzyme Q10 from over-the-counter supplements. Nutr Res. 2002:22(8):919-929.
- Bhagavan HN, Chopra RK. Plasma coenzyme Q10 response to oral ingestion of coenzyme Q10 formulations. Mitochondrion. 2007 Jun;7 Suppl:S78-88.
- Mohr D, Bowry VW, Stocker R. Dietary supplementation with coenzyme Q10 results in increased levels of ubiquinol-10 within circulating lipoproteins and increased resistance of human low-density lipoprotein to the initiation of lipid peroxidation. Biochim Biophys Acta. 1992 Jun 26;1126(3):247-54.
- Shoko D, Fujii K, Kurihara T. The effect of the reduced form of coenzyme Q10 (Ubiquinol, Kaneka QH™ ) on QOL improvement in the elderly. J Clin Therap Med. 2008; 24:233-238.
- Schmelzer C, Niklowitz P, Okun JG, Haas D, Menke T, Döring F. Ubiquinol-induced gene expression signatures are translated into altered parameters of erythropoiesis and reduced low density lipoprotein cholesterol levels in humans. IUBMB Life. 2011 Jan;63(1):42-8.
- Hosoe K, Kitano M, Kishida H, Kubo H, Fujii K, Kitahara M. Study on safety and bioavailability of ubiquinol (Kaneka QH) after single and 4-week multiple oral administration to healthy volunteers. Regul Toxicol Pharmacol. 2007 Feb;47(1):19-28.
- Tang PH, Miles MV, DeGrauw A, Hershey A, Pesce A. HPLC analysis of reduced and oxidized coenzyme Q(10) in human plasma. Clin Chem. 2001 Feb;47(2):256-65.
- Yamashita S, Yamamoto Y. Simultaneous detection of ubiquinol and ubiquinone in human plasma as a marker of oxidative stress. Anal Biochem. 1997 Jul 15;250(1):66-73.
- Bhagavan HN, Chopra RK. Coenzyme Q10: absorption, tissue uptake, metabolism and pharmacokinetics. Free Radic Res. 2006 May;40(5):445-53.