TweetDefinitely do not use Clen and an ECA formula such as ripped fuel simultaneously...alternate clen with the ripped fuel every two weeks...as for dosages with the clen, they vary from individual to individual..if they're the 20 mcg tabs,start off with a tab a day and increase by one each day until you find your tolerance level...Clen/ECA alternated every two weeks for 8-10 weeks...hope this helps