Ubiquinol

Ubiquinol is the reduced form of coenzyme Q10, priced and marketed as the version your body can use without a conversion step. The head-to-head evidence is thinner and more contradictory than the price gap suggests. One crossover trial in ten older men found 200mg a day of ubiquinol raised plasma CoQ10 about 1.5-fold while ubiquinone barely moved it. A three-period crossover in 21 adults aged 65 to 74, at a single 100mg dose, found ubiquinol no better than ubiquinone, and a water-soluble ubiquinone syrup better than either. That second study also reported CoQ10 turning up in blood mostly as ubiquinol whichever form was swallowed. Both are fat-soluble, so the meal you take them with is a bigger lever than the word on the bottle. CoQ10 has no reference intake in the UK, EU or US because it is not an essential nutrient, and if you take warfarin it belongs on the list you raise with your doctor first.

Stack Almanac marks ubiquinol as fat-soluble and times the reminder to a meal, because for a lipophilic molecule that is the absorption variable fully under your control.