In our country, almost every cancer patient must have health care products, from those given by friends, bought by themselves, or even prescribed by some doctors. We all hope that patients can maintain good health to receive treatment and hope that they will recover soon, and think that health care products are the best help they can provide to patients. However, most people do not know how to buy health supplements properly and how to use them reasonably. Health care products should be called “health food”: “Food Hygiene Law of the People’s Republic of China” stipulates that health food refers to food that indicates specific health care functions. That is, suitable for a specific group of people to eat, with the function of regulating the body, not for the purpose of treating disease food. In order to rectify and standardize the pharmaceutical market, since January 1, 2004, health care drugs have been removed from the market, and there is a clear division between health food and drugs, and drugs have been classified as pharmaceuticals. “The health food has an approval number. Health food has approval number, health food logo, etc. Surgery, chemotherapy, radiotherapy, immunotherapy and standardized Chinese medicine treatment are the conventional treatments for cancer that are recognized by the medical profession in China. Unconventional treatments are those treatments whose efficacy is not unanimously recognized by the medical community and have a great impact on the medical treatment behavior of cancer patients. At present, it has become a common medical phenomenon for cancer patients to receive unconventional treatment. There are misunderstandings about health food: 1. Misunderstanding health food as medicine. In fact, health food is only to help patients or normal people to supplement the nutrition and trace elements needed by human body, these health food are absolutely not drugs and cannot and will not replace them. It is the primary choice to receive conventional cancer treatment to control the disease, improve the quality of life and prolong the survival period. 2. Listening to health food advertisement and propaganda. The most important reason for cancer patients to use health food is to listen to the advertisement propaganda rather than the doctor’s advice. Some health food products violate the provisions of the Food Sanitation Law and take advantage of consumers’ psychology, claiming to have therapeutic effect on cancer and bow} up patients’ interest. 3. Misconception that health food is safe and non-toxic. Many cancer patients think that surgery, radiotherapy and chemotherapy have great side effects and health food is safe and non-toxic. In fact, excessive consumption of certain health food may also cause chronic accumulation or dependence, and certain health food ingredients are complex, and cancer patients do not pay attention to dietary contraindications when taking them, and the unreasonable joint application with therapeutic drugs may lead to adverse reactions.