Diabetes is not a contraindication to L-carnitine, diabetic patients can take L-carnitine, it is recommended to do so under the guidance of a doctor. L-carnitine belongs to weight loss drugs, which can promote fat conversion and reduce fat proliferation, all can play a role in weight loss. But there are some adverse reactions to L-carnitine, such as cardiac arrhythmia, dyspnea, dizziness, abdominal pain, diarrhea and so on. It is contraindicated for pregnant and lactating women, children and adolescents. Other patients should take it correctly under the guidance of physician’s interview and pay attention to the adverse reactions of the drug. Diabetic patients who eat L-carnitine appeared to be unwell, it is recommended to actively seek medical attention, patients should not self-medication to avoid adverse results.