Ubiquinol is the preferred form of CoQ10 and is better value than ubiquinone, per absorbed milligram. Ubiquinone may cause some side effects at high doses (eg. 1200 mg), however, as ubiquinol supplementation can give these same high blood levels at much lower doses, the potential for side effects is also much reduced. Ubiquinol has been shown to peak blood levels 6 hours after ingestion.