A double-blind comparator-controlled Phase I/II clinical trial of using D-linoleic acid ethyl ester (RT001) for Friedreichs ataxia, sponsored by Retrotope and Friedreichs Ataxia Research Alliance, was conducted to determine the safety profile and appropriate dosing for consequent trials. RT001 was promptly absorbed and was found to be safe and tolerable over 28 days at the maximal dose of 9 g/day. It improved peak workload and peak oxygen consumption in the test group compared to the control group who received the equal doses of normal, non-deuterated linoleic acid ethyl ester. Another randomised, double-blind, placebo-controlled clinical study began in 2019.