Thanks for your question. This is a question that we get asked often by our patients. The most common SIDE-EFFECTS of toxin injections include: Swelling, Redness, and Bruising at the site of injection. Complications are rare and only temporary, but may include paralysis of other nearby muscles, temporary eyelid ptosis (dropping of eyelids, 2% risk, lasts 2-3 weeks), temporary brow ptosis (dropping of eyebrows, 2% risk, lasts 2-3 weeks), cross-eyes, ectropion or edema of the lower eyelid, dry eyes, double vision, transient headaches (10%), local numbness (lasting 2-3 weeks), flu-like symptoms, rash at the injection site, pain at the injection site, infections, and bruising (need to avoid blood thinning medications). Cold compresses may be used immediately after treatment to reduce swelling only if needed. This may be applied for 3 minutes, 3 times per day, for up to 3 days. This is best done with a bag of peas in a zip lock bag. Only apply light pressure to the area. Only take Tylenol if you get a headache or migraine.