Reductil (sibutramine hydrochloride) is a highly-efficient medication that is supposed to be taken by people suffering from obesity, including obesity associated with certain health problems, such as diabetes, high blood pressure and high cholesterol. Mild and serious side effects are possible when you take Reductil, although serious side effects are quite rare. Such symptoms as constipation, increased blood pressure, increased sweating, headache, increased heart rate, dry mouth, and insomnia are considered to be mild and are not supposed to be reported to your health care provider unless they become very bothersome or prevent you from doing your everyday activities. Serious side effects may include some of the following: irregular heartbeats, sweating, disorientation, vomiting, lightheadedness, muscle stiffness, nervousness, depression, restlessness, shortness of breath, nausea, dilated pupils, mental confusion, and loss of muscle coordination. It’s impossible to predict all the possible side effects that may occur, so if you notice any that seem particularly bothersome but are not listed anywhere – call your doctor to learn what you are supposed to do in that case.