Oral Leflunomide weight loss is mostly due to the side effects of the drug, can be relieved by adjusting the diet, improve lifestyle habits, etc., if necessary, timely medical treatment. Leflunomide is a kind of immunosuppressant, also has the effect of anti-inflammatory, in the clinic is mainly used for the treatment of adult rheumatoid arthritis. Adverse reactions such as diarrhea, dyspepsia, pruritus, reversible elevation of liver enzymes, alopecia, and rash may occur when taking Leflunomide. Gastrointestinal adverse reactions due to this medication may affect the patient’s normal digestive and absorptive functions, affecting the patient’s absorption of nutrients and leading to weight loss. Usually, if the weight reduction is not obvious and there is no other obvious discomfort, the diet structure can be adjusted to maintain a light diet, balanced nutrition, eat more fresh fruits and vegetables, eggs, milk, etc. in moderation, drink more water, exercise more, ensure enough rest, avoid staying up late, etc., which can be alleviated to a certain extent, and with the prolongation of the time of taking the drug, the organism will gradually adapt to the drug, and generally do not need special treatment. If the patient in the weight loss at the same time, also accompanied by obvious diarrhea, rash, nausea, vomiting and other discomforts, and long-term can not be relieved, need to consult a doctor in time, under the guidance of the doctor to carry out reasonable treatment, if necessary, can be adjusted to the use of drugs. Leflunomide should be used in advance to consult a doctor, strictly in accordance with the doctor’s instructions to take, not self-medication, in order to avoid delay or even aggravate the condition.