Botulinum toxin mainly interferes with and inhibits the nerve conduction, blocks the connection between nerves and muscles, so that the signals from the central nervous system of the brain cannot be conveyed to the muscles, and loses its dominant effect on the muscles, so that when making expressions such as frowning and raising the head, the muscles do not respond accordingly, and wrinkles naturally do not arise. The effect of one Botox injection lasts for about 6 months. To maintain the effect, it can be repeatedly injected, but there should be an interval of 3-6 months between injections. When injecting botulinum toxin must be carefully chosen, do not go to unqualified beauty salons for injection, otherwise the following hazards may occur: 1, improper injection leads to nerve numbness, serious cases will damage the facial nerve, and long-term use will lead to symptoms of premature aging; 2, because it is a kind of allogeneic protein, and beauty salons and other non-medical institutions can not be screened for beauty seekers, allergic people may produce after injection 3, the operator should master the injection dose, but also need to strictly according to the injection method, site, level, etc. Improper operation may lead to the facial muscle disorder of the applicant, such as the injection of forehead lines, if the injection site is too close, it may lead to the eyes can not be opened; 4, the source of the product, the quality may produce problems, should choose the country allows the use of formal products, if the use of Irregular products, a greater harm may occur. Therefore, it is recommended that candidates choose a regular hospital and have injections under the operation of a professional doctor in order to obtain safe and effective cosmetic results.