Peptide deficiency affects hormone synthesis, cellular function, and substance transportation, etc. These physiological activities are crucial to all human systems, so peptide deficiency in the human body may lead to multi-system symptoms, mainly in the nervous system, immune system, and endocrine system.1. Neurological Symptoms: Peptide deficiency affects peptide neurotransmitter synthesis in the human body, which affects the process of synaptic transmission, and induces neurological symptoms, resulting in a slow response, memory loss, slow action, etc. 2, 2, immune system symptoms: peptide deficiency affects antibody synthesis and humoral immunity, leading to abnormal immune regulation, when the body is infected, it is difficult to resist the attack of pathogenic microorganisms, which can easily induce discomfort, headache, dizziness, fatigue, joint swelling and other symptoms; 3, endocrine system symptoms: peptide deficiency also affects the body’s secretion of peptide hormones such as growth hormone, thus affecting the metabolism. Growth hormone, thus affecting the body’s metabolism, is not conducive to growth and development, there may be delayed bone development, short, fat appearance and other dwarfism, may also cause endocrine disorders, insomnia, headache, menstrual disorders, aging and other manifestations. In addition, peptide deficiency can also cause a decrease in active substances, nutrient absorption disorders, malfunction of cellular regulation, slow metabolism, etc. Severe peptide deficiency may even be life-threatening. Patients need to consult the doctor in time, receive professional treatment as soon as possible, and supplement foods rich in high-quality protein, such as eggs, fish, and so on.