Natural Factors Ubiquinol QH Active CoQ10 is a powerful antioxidant that offers enhanced absorption and bioavailability especially for the aging body when the ability to naturally produce ubiquinol may be diminished. CoQ10 exists in two interchangeable forms; ubiquinone and ubiquinol. In the body, 95% of the circulating CoQ10 is the ubiquinol form. While ubiquinone solubilized in oil in softgel capsules has an excellent history of success in clinical studies, ubiquinol is gaining market share as it is significantly more soluble than common forms of ubiquinone (Natural Factors BioQ10 SA is the exception). This improved solubility results in enhanced and more consistent absorption of CoQ10, especially in the conditions where higher blood levels are desired (e.g., neurodegenerative disorders like Parkinson's disease.)