It makes my pores small and drys up my skin's usual oiliness immediately (within an hour). It may take a week or two of use to get rid of all acne if I'm already particularly broken out, but it prevents any new pimples from forming. If I only have a tiny amount of acne, it clears my skin within a couple days. And it works no matter what I eat as long as I take it within a few hours of eating acnegenic foods (peanut butter, nuts, milk chocolate, trans-fat foods, etc.).
I only take 1-10 mg, which is smaller than a match head. That's just a 1 mm spot of powder if you get the bulk powder, which is what I would do because regular tablets are always huge amounts--like 500 mg. And it would be hard to break a tablet into such small amounts. Well, I suppose you could crush it and just take little bits of the powder. A container of the bulk powder (500 g) will last for decades at the rate I use it. I am completely amazed by this stuff, especially because I was not expecting it to have this effect on my acne. It's pretty much miraculous. I had not seen this effect of ALCAR mentioned elsewhere ever. I have only ever seen it recommended for glucose tolerance and fat burning/weight loss. Initially I was trying it just to see if it helped with my hypoglycemia (which, incidentally, it didn't help very much).
I read about it online a little. It occurs in our bodies naturally in every cell, where it shuttles fatty acids into mitochondria where they are metabolized. I think it keeps fatty acids from building up in cells preventing energy metabolism blockages and necrosis of adipocytes in follicles, which is how it prevents acne, but I don't know.