Hello. Potential Botox side effects include pain at the injection site, infection, inflammation, swelling, redness, bleeding and bruising. Some of these symptoms may indicate an allergic reaction; other allergy symptoms are itching, wheezing, asthma, a rash, red welts, dizziness and faintness. Tell your doctor immediately if you have any breathing issues or a faint or dizzy feeling. Also, dry mouth, fatigue, headache and neck pain have been reported. You may have heard of other side effects as well, such as numbness, droopy eyelids, muscle spasms or twitching, and migration of the substance. Numbness as an absence of physical sensation is not really an issue with Botox, because Botox is not an anesthetic. Numbness as the result of the inability to move a muscle is an issue for some people. Muscle spasms in the area of the Botox injections do not occur while the Botox is effective. After all, Botox is used to treat spasms related to benign essential blepharospasm, hemifacial spasm, cerebral palsy, fibromyalgia and temporomandibular joint disorder. It is possible for the Botox to spread a little beyond the intended injection site and affect surrounding tissues. For example, if you receive injections into the forehead close to your eyebrows or your upper eyelids, they could be affected and may droop temporarily. regards- Dr Sanjay Kini