Transfer factor mainly has the function of boosting the number of immune cells, enhancing the function of immune cells and improving the body’s ability to resist diseases, and can be divided into two types of oral drugs and injections. Transfer Factor may induce adverse reactions after use, so it is not suitable for people who are allergic to the drug and its ingredients. In addition, special groups of people should use it under the guidance of doctors because the specific side effects are not clear. 1, allergic people: the main components of transfer factor include peptides, polynucleic acids, etc. For people who have had allergies to transfer factor in the past, as well as those who are allergic to proteins, amino acids, nucleic acids and other components, they should avoid using transfer factor to avoid inducing allergic reactions, resulting in skin rashes, nausea, vomiting, headaches, and even anaphylaxis. 2. Special populations: It is uncertain whether transfer factor will have adverse effects on pregnant women, lactating women, children, the elderly, and those who are taking other drugs, so such patients should ask their doctors and follow medical advice before using the drug. Before taking transfer factor, patients should check the date of manufacture, shelf life, and whether the outer packaging is normal. In addition, if adverse reactions such as fever, chest tightness, itchy skin or drowsiness occur during the use of the drug, the patient should stop using the drug and seek medical attention.