L-carnitine is an organic substance found in animal food, which plays an important role in the oxidation of fatty acids in the body and can accelerate the conversion of fatty acids into energy, so L-carnitine is often used to make weight loss food, but overdose of L-carnitine can have adverse effects on the circulatory system, digestive system, etc. The common hazards and side effects are as follows: 1. Circulatory system: overdose of L-carnitine, fat energy supply Too much makes the heart overload, may appear tachycardia, arrhythmia, panic and shortness of breath and other uncomfortable symptoms, and even easily induced arrhythmia. In addition to taking the crowd is mostly weight loss people, may also cooperate with dieting to achieve the effect of weight loss, which may make the heart discomfort more serious; 2, digestive system: L-carnitine promotes the conversion of fat into energy, will increase the burden on the kidneys and liver. Therefore, some users may experience gastrointestinal side effects such as indigestion, nausea, vomiting, abdominal pain, diarrhea and even loss of appetite; 3. Severe abdominal pain and diarrhea may lead to headache, dizziness, weakness, insomnia, thirst and other symptoms due to electrolyte disorders. Some patients may experience adverse reactions such as liver function impairment, lack of concentration, and skin irritation. If you want to lose weight through L-carnitine, you must take it under the guidance of a professional doctor and not on your own, otherwise it is likely to cause great harm to your body after overdosing. It is recommended that diet and exercise work together to achieve weight loss, not by taking L-carnitine.