Xenical is manufactured by Roche pharmaceuticals and is available in many parts of the world. Acomplia is also available in European countries since its approval by the European Union. Xenical slimming pills Xenical is a prescription slimming pill, which works in the digestive system of the body. Acomplia slimming pills Acomplia is the latest prescription slimming pill to be approved in the UK. These side effects are generally temporary and go away after few weeks of starting the treatment. It works in the hypothalamus part of the brain, which contains two neurotransmitters known as serotonin and noradrenaline. It contains Sibutramine as the main ingredient. Some prescription slimming pills have been quite effective in controlling obesity levels among people.