The original small (ie underpowered) study was published in 2002
This study reported:
." During the study period, the group that received the largest dose of coenzyme Q10 (1,200 mg/day) had 44 percent less decline in mental function, motor (movement) function, and ability to carry out activities of daily living, such as feeding or dressing themselves. The greatest effect was on activities of daily living. The groups that received 300 mg/day and 600 mg/day developed slightly less disability than the placebo group, but the effects were less than those in the group that received the highest dosage of coenzyme Q10. ..
The results of this study suggest that doses of coenzyme Q10 as high as 1,200 mg/day are safe and may be more effective than lower doses, says Dr. Shults.
I am aware there have been larger clinical trials using COQ10. as per the first posting, that trial was halted. not enough of those coq10 depleted statin users in the trials, i guess..
My husband uses 1200 MGM of coQ10/day in 3 divided doses.