I am 66 and my weight drifts around between 129-133. I run about 45-55mpw on average. I started taking 1000mg capsules about 6 months ago since maintaining stable weight is an endless struggle at my age. I haven't really noticed any significant effects positive or negative. Late last year my blood pressure started drifting up from normal 120-125/75-85 to 130-140/80-90. I have a family history of hypertension problems. I checked and some literature said L-Carnitine may cause increased BP. In mid-Feb I stopped the L-Carnitine, stopped taking the occasional Naprosyn, which also may increase BP, and stopped putting any salt on my food. MY BP now seems to be consistently 5+ points lower, not quite my old level but better. Again, I haven't noticed any real difference in my weight or running energy level since stopping the L-Carnitine. So, at the level I was taking it doesn't seem to do much, if anything.