I never liked Clen, but if you have to ask that questions the answer is always no. This is a hobby for 95% of us, a career for others. Regardless of your category the question is what comes first. For me its family and friends. Clen is not some type of silent killer their is a right/wrong way to do any thing even drinking water. But to be honest if you are considering any thing that has a direct effect on the function of your heart, it would be wise to see a doc, and at least get a full blood panel tested to see your present state. I know of IFBB pros who have gone as high as 600mcg/day of clen while maintaining health, but I'm sure a similar dose could kill others over time.