The principle of face slimming injection is by injecting a certain dose of botulinum toxin into the end plate of the bite muscle movement, paralyzing the muscle and weakening the function of movement, which will eventually produce disuse atrophy. The whole process takes some time, generally 1-2 weeks after the injection will play the initial effect, in about 2 months after the injection of the injection to achieve the best effect. Usually after 4-6 months, the muscle contraction function will be restored and the bite muscle may retract partly again and regain the contraction ability. Therefore, usually at 4-6 months, the doctor will recommend a second injection. Regarding the frequency of injections, the interval of 4-6 months after an injection is often recommended by doctors, which is actually more in line with the process of drug metabolism after a single injection. If high frequency injections are performed, the effect is the same as regular injections at a later stage. It is generally not recommended to go for short intervals and high frequency injections, but rather regular and moderate dosage of medication during the treatment period. Therefore, it is recommended that candidates visit a regular hospital to avoid adverse effects on the face due to problems such as drugs and doctor’s operation.