I have taken diet tablets for a long time. They always had ephedrine and caffeine in large dosages. I started when I was 17 years old because I was training on the elite team in martial arts. You get more alert, fast and strong by taking these pills. The training was everyday and I soon was addicted to these pills. No pills, no training (or life for that matter). Soon I got stronger and stronger dosages. My metabolism was fucked up after some years. I ate a lot because of high metabolism. Then I knew I had to stop taking the pills if I didn’t want a heart attack in an early age. Stopping the pills meant stopping the training. So I stopped from training every day, and taking the pills, in the same day. I slept and slept and slept for weeks. Still eating and now with a much lower metabolism and inactive lifestyle I gained weight. It took me a short time to "miss" the times when I had a lot of energy and was slim. I thought I’d rather die of heart attack than to be fat and tired. So I went of and on the pills several times. And every time I got more and more fat. This has been going on for now 16 years with the result of bad heart/lungs, overweight, depression and tiredness. I have only one good advice to you young people out there: Your body is NOT a playground for chemicals. Do not fuck with Mother Nature and think that anything not natural is good for you. Some day you want to get old with your partner and see your children grow up. If you play too much with your health, that is not possible. I recommend you to take NATURAL herbs like many of the products here on this site. The plants are here on this planet for you to enjoy. And if you get enough information about the plants, you will know what to take and how much. Mother Nature is the far most powerful provider of good experiences. No speed or (chemical processed) cocaine can beat the natural drug store we all have access too. So be smart and go for the natural experience.