I'm finishing up a bottle of N2Burn & it hasn't done anything for me. I stacked it with some raspberry ketones, as well as some other basic supplements I take. Granted, I'd had to stop taking it right after opening the bottle, due to an upper respiratory infection I had in January & February, but I still had most of the capsules when I started taking it again in April. I did a LOT of outdoor physical work during the month of April & thought taking N2Burn at the same time would both boost my energy levels & dramatically increase fat burning. It didn't. I'm 53 years old, so maybe my age is why it didn't work. But I think I remember asking the manufacturer what would be best for me to use to lose weight. I guess they were wrong. Another huge waste of money (for me, at least) and time.