I had my doubts about their actual effect on metabolism and fat burning effect so I bought them mainly because they have lots of caffeine and energy drinks are expensive but I must say I'm plesently surprised. The way they work (for me at least) is that they surprises my appetite a lot aswell as both my cravings for sweets and surprisingly also nicotine. The high caffeine prevent the feeling of being tired and I don't get cold from eating too little like I would before (idk if it's due to the pills, environmental factors or my other medications). Taking more than one wouldn't work since they're only active until they're out of your system and taking more wouldn't make them more effective (I'm mentioning this because it's common for people to assume it'll work better if you take more but in this case it would only lead to a caffeine overdose). Since they surpress my appetite and cravings for sweets I eat much less which is the main reason for weight loss. I've taken them once a day, in the morning, with my breakfast consisting of a large smoothie and a cheese sandwich at around 8am . Then I don't eat until around 6pm-9pm (depending on what I'm doing and when I get hungry), and then I eat another cheese sandwich and have another large smoothie for dinner. If I get a bit peckish before dinner I'll have an apple or a banana and I'll do the same after dinner if needed. First time I tried it was Saturday and it's now Wednesday. I started taking them on a day where I'd be home so if I reacted badly it wouldn't effect my day or prevent me from doing what I was supposed to, if you want to try these I suggest you do the same. It's worth mentioning that I have ADHD amongst other diagnosises which means I react differently to things so the effects may be different to NT people. It doesn't completely remove all cravings so you still need to have some willpower. It's not a magic pill. All I'm sure it does is surpress your appetite and give you energy from the caffeine in the product. Your body won't feel the need to eat sugary things but your brain might still want to so that's where you have to make an active choice to choose a healthy option as a snack over a sugary treat like chocolate. It won't lose weight for you but it will help you do it yourself. It works well for me at the moment and might work for you as well. It's much cheaper than energy drinks so if you have some extra cubb on ya and also drink lots of coffee or energy drinks to get your caffeine fix I'd say it's worth a shot.