Be careful with Alcar and any carnitine it can cause symptoms of hypothyroidism in some and can disrupt t4 to t3 conversion I believe, don't quote me on this. I only recommend using it under a doctor's supervision. I witness this firsthand I started to get poor sleep, sluggish metabolism and cold body temps from using within in a week. I gainned 12 pounds within a short time as well( a couple months)after use. My metabolism is still some what sluggish. I was on the same diet and light exercises regimen. I used it in the past with no problem but every time I used it it screws with my metabolism and body temperature. I have no bloods to prove it, it's just speculation but I would stay far from it if you have any thyroid related problems.