Please don't do it year round. I wouldn't even touch one pill. My old training partner retired at 29 because his left vent chamber is enlarged. He is afraid of caffeine now. Before he used to take clen beginning in January till August with 2 weeks on 2-3 weeks off and never did more than 100mcg's. This plus 5-10 iu's of gh p/w for 2 years and boom, now has hard time climbing steps, but before he went for military service he was checked to be completely healthy. No rec drugs either. So he claims it's clen+gh. I used to play with it once in a while but now I'm of different opinion. I don't say that's what waits for all who take clen, some are lucky, and some are not so. Use your best judgement.
God Bless,
TT