Clen is not harmful for humans, but like lots of other meds you need a perscription for it or must find other means to get it. It is a broncial drug. but may aid in fat loss. Both my husband and I have taken it. He had more success than I did. We are both in good shape and wanted to loose a little body fat for summer. You must cycle clen, or your body will get used to it. Pretty much it raised you body temperature. This normally last for about a two week period, then you body gets used to it and brings your temperature back down. I used a two week on, two week off schedule and so did my husband. I will probably use it again, at one point or another in my life, but for now I'm not ready to sweat like that again. It pretty much makes you feel really hot. fever hot and you feel like your sick. But we will all do crazy things to look good in a bathing suit!! Good luck if you take it and let me know your results!