Cosmetic doses of Botox injections are very safe, and adverse reactions are rare and generally mild and transient. There have been no reported clinically irreversible adverse reactions caused by botulinum toxin. Current studies have shown that adverse reactions or complications from botulinum toxin are often due to incorrect injection methods, or local dispersion of botulinum toxin. Therefore, the prevention of complications should improve the injection technique and precision, and try to confine its action within the target site. 1. Injection reactions. The injection itself has the potential to cause adverse reactions including, redness, pain, erythema, swelling, bruising, etc. Surface anesthesia before injection, the use of small injection needles, and cold compresses after injection can significantly reduce such adverse reactions. 2. Atopic reactions. Botulinum toxin injection may also lead to atopic reactions, including headache, cold symptoms, nausea, rash, itching, allergic reactions, etc., which can generally heal on their own. 3.Brow sagging. It is the most important adverse reaction in forehead wrinkle injection. For elderly patients who already have skin laxity on the upper lid, it will lead to pseudo ptosis and difficulty in opening the upper lid due to eyebrow ptosis. The way to prevent this is to note that no injections should be given within the frontalis muscle two centimeters above the arch of the eyebrow. 4. Ptosis. Often secondary to frontal or frown muscle injections, botulinum toxin diffuses downward into the orbit, causing paralysis of the levator muscle. If ptosis occurs, you can usually only wait for it to recover on its own. Treatment with eye drops of alpha-adrenergic agonists can stimulate the mullerian muscle and increase the size of the eyelid fissure for 2-3 hours. Injections around the upper lid need to avoid excessive diffusion of the drug, and care must also be taken not to massage the injection area. 5. Strabismus and diplopia. When Botox is injected around the eye, the extraocular muscles are paralyzed because the drug diffuses into the orbit. The method of prevention is to use an auxiliary hand to compress the orbital rim during injection to prevent drug dispersion. 6. Incomplete eyelid closure. Lower lid recession. It is caused by paralysis of the orbicularis oculi muscle due to Botox injection. A reasonable choice of indications is required. Lower lid injections are not suitable for patients with too much skin laxity, as well as patients who have had lower lid surgery, or who have poor lower lid elasticity, and try to avoid intramuscular injections in the orbicularis muscle of the lower lid plate portion of the eyelid when injecting. 7, expression stiffness, mostly caused by the involvement of botulinum toxin in the middle of the face, the middle of the face is a concentrated area of expression muscles, if directly injected into the middle of the face, or the drug diffusion to the middle of the face (such as crows feet injection position is too low, bite muscle injection position is too shallow), can cause facial stiffness. In addition, the facial stiffness can be caused by the injection of botulinum toxin into the middle of the face or by the diffusion of the drug into the middle of the face (e.g., low position of crows feet injection, too shallow position of bite muscle injection). The prevention method is to reduce the amount of Botox, to inject in the subcutaneous superficial layer, and bilateral symmetry, using low dose injection. Other 1. Long-term use. Large data analysis shows that long-term use of botulinum toxin does not lead to significant adverse reactions, and individual patients may experience focal muscle weakness. 2, combined application. In addition to simple dynamic wrinkles, many manifestations of aging in the face require combined other treatments, including: dermal filler fat grafting, laser photoelectric treatment, surgical treatment, etc. In the combined application of Botox injection and other treatments, care needs to be taken to avoid other treatments promoting Botox dispersion, and attention should be paid to the sequence, or to avoid combined treatments on the same day.